Provided by: fetchmail_6.4.32-1_amd64 bug


       fetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server


       fetchmail [option...] [mailserver...]


       fetchmail  is  a  mail-retrieval  and forwarding utility; it fetches mail from remote mail
       servers and forwards it to your local (client) machine's delivery system.   You  can  then
       handle  the  retrieved  mail  using  normal  mail  user  agents such as mutt(1), elm(1) or
       Mail(1).  The fetchmail utility can be run in a daemon mode to repeatedly poll one or more
       systems at a specified interval.

       The  fetchmail  program  can  gather  mail from servers supporting any of the common mail-
       retrieval protocols: POP2 (legacy, to be removed from  future  release),  POP3,  IMAP2bis,
       IMAP4,  and  IMAP4rev1.   It  can  also  use the ESMTP ETRN extension and ODMR.  (The RFCs
       describing all these protocols are listed at the end of this manual page.)

       While fetchmail is primarily intended to be used over on-demand TCP/IP links (such as SLIP
       or  PPP  connections),  it  may also be useful as a message transfer agent for sites which
       refuse for security reasons to permit (sender-initiated) SMTP transactions with sendmail.


       For troubleshooting, tracing and debugging, you need to increase fetchmail's verbosity  to
       actually  see  what  happens.  To  do that, please run both of the two following commands,
       adding all of the options you'd normally use.

              env LC_ALL=C fetchmail -V -v --nodetach --nosyslog

              (This command line prints in English how fetchmail understands your configuration.)

              env LC_ALL=C fetchmail -vvv  --nodetach --nosyslog

              (This command line actually runs fetchmail with verbose English output.)

       Also  see  item  #G3  in  fetchmail's   FAQ   ⟨

       You  can  omit  the  LC_ALL=C  part  above  if  you  want output in the local language (if
       supported). However if you  are  posting  to  mailing  lists,  please  leave  it  in.  The
       maintainers do not necessarily understand your language, please use English.


       Your  fetchmail  distribution  should  have come with a README.SSL file, which see.  It is
       recommended to configure all polls with --ssl  --sslproto  tls1.2+  if  supported  by  the
       server,  which  configures fetchmail along recent IETF proposed standards and best current
       practices, RFC-8314, RFC-8996, RFC-8997.


       If fetchmail is used with a POP or an IMAP server (but not with ETRN or ODMR), it has  two
       fundamental  modes  of  operation  for  each  user  account  from which it retrieves mail:
       singledrop- and multidrop-mode.

       In singledrop-mode,
              fetchmail assumes that all messages in the user's account  (mailbox)  are  intended
              for  a  single recipient.  The identity of the recipient will either default to the
              local user currently executing fetchmail, or will need to be  explicitly  specified
              in the configuration file.

              fetchmail  uses singledrop-mode when the fetchmailrc configuration contains at most
              a single local user specification for a given server account.

       In multidrop-mode,
              fetchmail assumes that the mail server account actually contains mail intended  for
              any  number  of  different recipients.  Therefore, fetchmail must attempt to deduce
              the proper "envelope recipient" from the mail headers of  each  message.   In  this
              mode of operation, fetchmail almost resembles a mail transfer agent (MTA).

              Note that neither the POP nor IMAP protocols were intended for use in this fashion,
              and hence envelope information is often not directly available. The ISP must  store
              the  envelope  information  in some message header and. The ISP must also store one
              copy of the message per recipient. If either of the conditions  is  not  fulfilled,
              this process is unreliable, because fetchmail must then resort to guessing the true
              envelope recipient(s) of a message. This usually fails for  mailing  list  messages
              and Bcc:d mail, or mail for multiple recipients in your domain.

              fetchmail  uses  multidrop-mode  when more than one local user and/or a wildcard is
              specified for a particular server account in the configuration file.

       In ETRN and ODMR modes,
              these considerations do not apply, as these protocols  are  based  on  SMTP,  which
              provides  explicit  envelope  recipient information. These protocols always support
              multiple recipients.

       As each message is retrieved, fetchmail normally delivers it via SMTP to port  25  on  the
       machine it is running on (localhost), just as though it were being passed in over a normal
       TCP/IP link.  fetchmail provides the SMTP server with an envelope recipient derived in the
       manner  described  previously.   The  mail  will then be delivered according to your MTA's
       rules (the Mail Transfer Agent is usually sendmail(8), exim(8), or postfix(8)).   Invoking
       your system's MDA (Mail Delivery Agent) is the duty of your MTA.  All the delivery-control
       mechanisms (such as .forward files) normally available through your system MTA  and  local
       delivery agents will therefore be applied as usual.

       If  your  fetchmail configuration sets a local MDA (see the --mda option), it will be used
       directly instead of talking SMTP to port 25.

       If the program fetchmailconf is available, it will assist you in setting up and editing  a
       fetchmailrc  configuration.   It  runs  under  the  X  window system and requires that the
       language Python and the Tk toolkit (with Python bindings) be present on your  system.   If
       you  are  first  setting up fetchmail for single-user mode, it is recommended that you use
       Novice mode.  Expert mode provides complete control of fetchmail configuration,  including
       the  multidrop  features.   In  either case, the 'Autoprobe' button will tell you the most
       capable protocol a given mail server supports, and warn you  of  potential  problems  with
       that server.


       Fetchmail's  run-time  strings have been translated (localized) to some languages, but the
       manual is only available in English.  In some situations, for comparing output to  manual,
       it  may  be  helpful  to  switch  fetchmail  to  English  output  by overriding the locale
       variables, for instance:

              env LC_ALL=C fetchmail # add other options before the hash

              env LANG=en fetchmail # other options before the hash

       or similar. Details vary by operating system.


       The behavior of fetchmail is controlled by command-line options and a  run  control  file,
       ~/.fetchmailrc,  the syntax of which we describe in a later section (this file is what the
       fetchmailconf program edits).  Command-line options override ~/.fetchmailrc declarations.

       Each server name that you specify following the  options  on  the  command  line  will  be
       queried.  If you do not specify any servers on the command line, each 'poll' entry in your
       ~/.fetchmailrc file will be queried, unless the idle option is used, which see.

       To facilitate the use of fetchmail in scripts and pipelines,  it  returns  an  appropriate
       exit code upon termination -- see EXIT CODES below.

       The following options modify the behavior of fetchmail.  It is seldom necessary to specify
       any of these once you have a working .fetchmailrc file set up.

       Almost all options have a corresponding keyword which can be used to  declare  them  in  a
       .fetchmailrc file.

       Some  special  options  are  not  covered  here, but are documented instead in sections on
       AUTHENTICATION and DAEMON MODE which follow.

   General Options
       -? | --help
              Displays option help.

       -V | --version
              Displays the version information for your copy of  fetchmail.   No  mail  fetch  is
              performed.   Instead,  for  each  server specified, all the option information that
              would be computed if fetchmail were connecting to that server  is  displayed.   Any
              non-printable  characters  in  passwords  or  other string names are shown as back-
              slashed C-like escape sequences.  This option is useful  for  verifying  that  your
              options are set the way you want them.

       -c | --check
              Return  a  status  code to indicate whether there is mail waiting, without actually
              fetching or deleting mail (see EXIT CODES below).  This  option  turns  off  daemon
              mode  (in  which  it  would  be  useless).   It  does not play well with queries to
              multiple sites, and does not work with ETRN  or  ODMR.   It  will  return  a  false
              positive if you leave read but undeleted mail in your server mailbox and your fetch
              protocol cannot tell kept messages from new ones.  This means  it  will  work  with
              IMAP, not work with POP2, and may occasionally flake out under POP3.

       -s | --silent
              Silent  mode.   Suppresses all progress/status messages that are normally echoed to
              standard output during a fetch (but does not suppress actual error messages).   The
              --verbose option overrides this.

       -v | --verbose
              Verbose  mode.   All  control messages passed between fetchmail and the mail server
              are echoed to stdout.  Overrides --silent.  Doubling this  option  (-v  -v)  causes
              extra diagnostic information to be printed.

              (since v6.3.10, Keyword: set no softbounce, since v6.3.10)
              Hard  bounce  mode. All permanent delivery errors cause messages to be deleted from
              the upstream server, see "no softbounce" below.

              (since v6.3.10, Keyword: set softbounce, since v6.3.10)
              Soft bounce mode. All permanent delivery errors cause messages to be  left  on  the
              upstream  server  if  the  protocol supports that.  This option is on by default to
              match historic fetchmail documentation, and will be changed to hard bounce mode  in
              the next fetchmail release.

   Disposal Options
       -a | --all | (since v6.3.3) --fetchall
              (Keyword: fetchall, since v3.0)
              Retrieve  both old (seen) and new messages from the mail server.  The default is to
              fetch only messages the server has not marked seen.  Under POP3, this  option  also
              forces the use of RETR rather than TOP.  Note that POP2 retrieval behaves as though
              --all is always on (see RETRIEVAL FAILURE MODES below) and  this  option  does  not
              work  with  ETRN  or ODMR.  While the -a and --all command-line and fetchall rcfile
              options have been supported for a long time, the --fetchall command-line option was
              added in v6.3.3.

       -k | --keep
              (Keyword: keep)
              Keep  retrieved messages on the remote mail server.  Normally, messages are deleted
              from the folder on the mail server after they have been retrieved.  Specifying  the
              keep  option causes retrieved messages to remain in your folder on the mail server.
              This option does not work with ETRN or ODMR. If used with POP3, it  is  recommended
              to also specify the --uidl option or uidl keyword.

       -K | --nokeep
              (Keyword: nokeep)
              Delete  retrieved  messages  from  the  remote  mail  server.   This  option forces
              retrieved mail to be deleted.  It may be useful if you have specified a default  of
              keep in your .fetchmailrc.  This option is forced on with ETRN and ODMR.

       -F | --flush
              (Keyword: flush)
              POP3/IMAP  only.   This  is  a  dangerous  option and can cause mail loss when used
              improperly. It deletes old (seen) messages from the mail server  before  retrieving
              new  messages.  Warning: This can cause mail loss if you check your mail with other
              clients than fetchmail, and cause fetchmail  to  delete  a  message  it  had  never
              fetched  before.   It can also cause mail loss if the mail server marks the message
              seen after retrieval (IMAP2 servers). You should probably not use  this  option  in
              your  configuration  file. If you use it with POP3, you must use the 'uidl' option.
              What you probably want is the default setting: if you do  not  specify  '-k',  then
              fetchmail will automatically delete messages after successful delivery.

              POP3/IMAP  only,  since  version  6.3.0.   Delete  oversized messages from the mail
              server before  retrieving  new  messages.  The  size  limit  should  be  separately
              specified with the --limit option.  This option does not work with ETRN or ODMR.

   Protocol and Query Options
       -p <proto> | --proto <proto> | --protocol <proto>
              (Keyword: proto[col])
              Specify  the protocol to use when communicating with the remote mail server.  If no
              protocol is specified, the default is AUTO.  proto may be one of the following:

              AUTO   Tries IMAP, POP3, and POP2 (skipping any of these for which support has  not
                     been compiled in).

              POP2   Post Office Protocol 2 (legacy, to be removed from future release)

              POP3   Post Office Protocol 3

              APOP   Use  POP3  with  old-fashioned MD5-challenge authentication.  Considered not
                     resistant to man-in-the-middle attacks.

              RPOP   Use POP3 with RPOP authentication.

              KPOP   Use POP3 with Kerberos V4 authentication on port 1109.

              SDPS   Use POP3 with Demon Internet's SDPS extensions.

              IMAP   IMAP2bis,  IMAP4,  or  IMAP4rev1  (fetchmail  automatically  detects   their

              ETRN   Use the ESMTP ETRN option.

              ODMR   Use the On-Demand Mail Relay ESMTP profile.

       All  these alternatives work in basically the same way (communicating with standard server
       daemons to fetch mail already delivered to a mailbox on the server) except ETRN and  ODMR.
       The  ETRN mode allows you to ask a compliant ESMTP server (such as BSD sendmail at release
       8.8.0 or higher) to immediately open a sender-SMTP connection to your client  machine  and
       begin  forwarding  any  items  addressed  to  your client machine in the server's queue of
       undelivered mail.   The ODMR mode requires an ODMR-capable server and works  similarly  to
       ETRN, except that it does not require the client machine to have a static DNS.

       -U | --uidl
              (Keyword: uidl)
              Force UIDL use (effective only with POP3).  Force client-side tracking of 'newness'
              of messages (UIDL stands for "unique ID listing" and is described in RFC1939).  Use
              with  'keep'  to  use  a mailbox as a baby news drop for a group of users. The fact
              that seen messages are skipped is logged, unless  error  logging  is  done  through
              syslog  while running in daemon mode.  Note that fetchmail may automatically enable
              this option depending on upstream server capabilities.  Note also that this  option
              may  be  removed  and  forced  enabled  in  a  future  fetchmail version. See also:

       --idle (since 6.3.3)
              (Keyword: idle, since before 6.0.0)
              Enable IDLE use (effective only with IMAP). Note that  this  works  with  only  one
              account  and  one  folder  at  a  given time, other folders or accounts will not be
              polled when idle is in effect!  While the idle rcfile keyword  had  been  supported
              for  a  long  time, the --idle command-line option was added in version 6.3.3. IDLE
              use means that fetchmail tells the IMAP server to send notice of new  messages,  so
              they can be retrieved sooner than would be possible with regular polls.

       -P <portnumber> | --service <servicename>
              (Keyword: service) Since version 6.3.0.
              The  service  option  permits you to specify a service name to connect to.  You can
              specify a decimal port number here, if your services database  lacks  the  required
              service-port  assignments.  See  the  FAQ  item R12 and the --ssl documentation for
              details. This replaces the older --port option.

       Note that this does not magically switch between TLS-wrapped and STARTTLS  modes,  if  you
       specify  a  port  number  or  service  name here that is TLS-wrapped, meaning it starts to
       negotiate TLS before sending application data in the clear, you may need to specify  --ssl
       on the command line or ssl in your rcfile.

       --port <portnumber>
              (Keyword: port)
              Obsolete  version of --service that does not take service names.  Note: this option
              may be removed from a future version.

       --principal <principal>
              (Keyword: principal)
              The principal option  permits  you  to  specify  a  service  principal  for  mutual
              authentication.   This is applicable to POP3 or IMAP with Kerberos 4 authentication
              only.  It does not apply to Kerberos 5 or GSSAPI.  This option may be removed in  a
              future fetchmail version.

       -t <seconds> | --timeout <seconds>
              (Keyword: timeout)
              The  timeout option allows you to set a server-non-response timeout in seconds.  If
              a mail server does not send a greeting message or respond to commands for the given
              number  of  seconds,  fetchmail  will  drop  the  connection to it.  Without such a
              timeout fetchmail might hang until the TCP connection times out,  trying  to  fetch
              mail from a down host, which may be very long.  This would be particularly annoying
              for a fetchmail running in the  background.   There  is  a  default  timeout  which
              fetchmail  -V  will  report.   If  a given connection receives too many timeouts in
              succession, fetchmail will consider it wedged and stop retrying.  The calling  user
              will be notified by email if this happens.

              Beginning  with  fetchmail  6.3.10,  the  SMTP  client uses the recommended minimum
              timeouts from RFC-5321 while waiting for the SMTP/LMTP server  it  is  talking  to.
              You can raise the timeouts even more, but you cannot shorten them. This is to avoid
              a painful situation where fetchmail has been configured with  a  short  timeout  (a
              minute  or  less),  ships a long message (many MBytes) to the local MTA, which then
              takes longer than timeout to respond "OK", which it  eventually  will;  that  would
              mean the mail gets delivered properly, but fetchmail cannot notice it and will thus
              re-fetch this big message over and over again.

       --plugin <command>
              (Keyword: plugin)
              The plugin option allows you to use  an  external  program  to  establish  the  TCP
              connection.   This  is useful if you want to use ssh, or need some special firewall
              setup.  The program will be looked up in $PATH and can  optionally  be  passed  the
              host  name  and  port  as arguments using "%h" and "%p" respectively (note that the
              interpolation logic is rather primitive,  and  these  tokens  must  be  bounded  by
              whitespace  or  beginning of string or end of string).  Fetchmail will write to the
              plugin's stdin and read from the plugin's stdout.

       --plugout <command>
              (Keyword: plugout)
              Identical to  the  plugin  option  above,  but  this  one  is  used  for  the  SMTP

       -r <name> | --folder <name>
              (Keyword: folder[s])
              Causes  a  specified non-default mail folder on the mail server (or comma-separated
              list of folders) to be retrieved.   The  syntax  of  the  folder  name  is  server-
              dependent.  This option is not available under POP3, ETRN, or ODMR.

              (Keyword: tracepolls)
              Tell  fetchmail  to  poll  trace  information  in the form 'polling account %s' and
              'folder %s' to the Received line it generates, where the %s parts are  replaced  by
              the  user's  remote  name, the poll label, and the folder (mailbox) where available
              (the Received header also normally includes the server's true name).  This  can  be
              used  to  facilitate mail filtering based on the account it is being received from.
              The folder information is written only since version 6.3.4.

       --ssl  (Keyword: ssl)
              Causes the connection to the mail server to be encrypted via  SSL,  by  negotiating
              SSL  directly  after  connecting  (called  SSL-wrapped  mode,  or  Implicit  TLS by
              RFC-8314).  Please see the description of --sslproto below!   More  information  is
              available in the README.SSL file that ships with fetchmail.

              Note that even if this option is omitted, fetchmail may still negotiate SSL in-band
              for POP3 or IMAP, through the STLS or STARTTLS feature.  You can use the --sslproto
              option to modify that behavior.

              If  no port is specified, the connection is attempted to the well known port of the
              SSL version of the base protocol.  This is generally a different port than the port
              used  by  the base protocol.  For IMAP, this is port 143 for the clear protocol and
              port 993 for the SSL secured protocol; for POP3, it is port 110 for the clear  text
              and port 995 for the encrypted variant.

              If  your  system  lacks  the  corresponding  entries  from  /etc/services,  see the
              --service option and specify the numeric port  number  as  given  in  the  previous
              paragraph  (unless  your ISP had directed you to different ports, which is uncommon

       --sslcert <name>
              (Keyword: sslcert)
              For certificate-based client authentication.  Some SSL  encrypted  servers  require
              client  side  keys  and  certificates  for  authentication.  In most cases, this is
              optional.  This specifies  the  location  of  the  public  key  certificate  to  be
              presented  to  the  server  at  the time the SSL session is established.  It is not
              required (but may be provided) if the server does not require it.  It  may  be  the
              same  file  as  the private key (combined key and certificate file) but this is not
              recommended. Also see --sslkey below.

              NOTE: If you  use  client  authentication,  the  user  name  is  fetched  from  the
              certificate's CommonName and overrides the name set with --user.

       --sslkey <name>
              (Keyword: sslkey)
              Specifies  the  file  name  of the client side private SSL key.  Some SSL encrypted
              servers require client side keys and  certificates  for  authentication.   In  most
              cases,  this  is  optional.  This specifies the location of the private key used to
              sign transactions with the server at the time the SSL session is  established.   It
              is  not required (but may be provided) if the server does not require it. It may be
              the same file as the public key (combined key and certificate file) but this is not

              If  a  password  is required to unlock the key, it will be prompted for at the time
              just prior to establishing  the  session  to  the  server.   This  can  cause  some
              complications in daemon mode.

              Also see --sslcert above.

       --sslproto <value>
              (Keyword: sslproto, NOTE: semantic changes since v6.4.0)
              This  option  has a dual use, out of historic fetchmail behaviour. It controls both
              the SSL/TLS protocol version and, if --ssl is not specified, the STARTTLS behaviour
              (upgrading  the  protocol  to an SSL or TLS connection in-band). Some other options
              may however make TLS mandatory.

              Only if this option  and  --ssl  are  both  missing  for  a  poll,  there  will  be
              opportunistic  TLS  for  POP3  and IMAP, where fetchmail will attempt to upgrade to
              TLSv1 or newer.

              Recognized values for --sslproto are given below. You should normally choose one of
              the auto-negotiating options, i. e. 'tls1.2+' or 'auto' or one of the other options
              ending in a plus (+) character.  Note that depending on OpenSSL library version and
              configuration,  some options cause run-time errors because the requested SSL or TLS
              versions are not supported by the particular installed OpenSSL library.

                     (recommended). Since v6.4.0. Require TLS. Auto-negotiate TLSv1.2 or newer.

              'auto' (default). Since v6.4.0. Require TLS. Auto-negotiate TLSv1 or newer, disable
                     SSLv3  downgrade.   (fetchmail  6.3.26  and  older  have auto-negotiated all
                     protocols that their OpenSSL library supported, including the broken SSLv3).

              '', the empty string
                     Disable STARTTLS. If --ssl is given for the same server, log  an  error  and
                     pretend that 'auto' had been used instead.

                     see 'auto'.

              'SSL3' Require  SSLv3 exactly. SSLv3 is broken, not supported on all systems, avoid
                     it if possible.  This will make fetchmail negotiate SSLv3 only, and  is  the
                     only way besides 'SSL3+' to have fetchmail 6.4.0 or newer permit SSLv3.

                     same  as  'auto',  but  permit  SSLv3  as well. This is the only way besides
                     'SSL3' to have fetchmail 6.4.0 or newer permit SSLv3.

              'TLS1' Require TLSv1. This does not negotiate TLSv1.1 or newer, and is discouraged.
                     Replace by TLS1+ unless the latter chokes your server.

                     Since v6.4.0. See 'auto'.

                     Since v6.4.0. Require TLS v1.1 exactly.

                     Since v6.4.0. Require TLS. Auto-negotiate TLSv1.1 or newer.

                     Since v6.4.0. Require TLS v1.2 exactly.

                     Since v6.4.0. Require TLS v1.3 exactly.

                     Since v6.4.0. Require TLS. Auto-negotiate TLSv1.3 or newer.

              Unrecognized parameters
                     are treated the same as 'auto'.

              NOTE:  you  should  hardly  ever  need  to  use anything other than '' (to force an
              unencrypted connection) or 'auto' (to enforce TLS).

              (Keyword: sslcertck, default enabled since v6.4.0)
              --sslcertck causes fetchmail to require that SSL/TLS be used and disconnect  unless
              it  can  successfully negotiate SSL or TLS, or if it cannot successfully verify and
              validate the certificate  and  follow  it  to  a  trust  anchor  (or  trusted  root
              certificate).  The  trust  anchors are given as a set of local trusted certificates
              (see the sslcertfile and sslcertpath options). If the server certificate cannot  be
              obtained  or  is  not  signed  by one of the trusted ones (directly or indirectly),
              fetchmail will disconnect, regardless of the sslfingerprint option.

              (Keyword: no sslcertck, only in v6.4.X)
              The opposite of --sslcertck, this is a discouraged option. It permits fetchmail  to
              continue  connecting even if the server certificate failed the verification checks.
              Should only be used together with --sslfingerprint.

       --sslcertfile <file>
              (Keyword: sslcertfile, since v6.3.17)
              Sets the file fetchmail uses to look up local certificates.  The default is  empty.
              This can be given in addition to --sslcertpath below, and certificates specified in
              --sslcertfile will be processed before those in --sslcertpath.  The option  can  be
              used in addition to --sslcertpath.

              The  file  is a text file. It contains the concatenation of trusted CA certificates
              in PEM format.

              Note that using this option will  suppress  loading  the  default  SSL  trusted  CA
              certificates     file     unless     you     set     the    environment    variable
              FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty value.

       --sslcertpath <directory>
              (Keyword: sslcertpath)
              Sets the directory fetchmail uses to look up local  certificates.  The  default  is
              your  OpenSSL  default  directory.  The  directory  must  be hashed the way OpenSSL
              expects it - every time you add or modify a certificate in the directory, you  need
              to  use  the  c_rehash tool (which comes with OpenSSL in the tools/ sub-directory).
              Also, after OpenSSL upgrades, you may need to run c_rehash.

              This can be given in addition to --sslcertfile  above,  which  see  for  precedence

              Note  that  using  this  option  will  suppress  adding  the default SSL trusted CA
              certificates    directory    unless    you    set    the    environment    variable
              FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty value.

       --sslcommonname <common name>
              (Keyword: sslcommonname; since v6.3.9)
              Use  of  this  option is discouraged. Before using it, contact the administrator of
              your upstream server and ask for a proper SSL  certificate  to  be  used.  If  that
              cannot  be  attained, this option can be used to specify the name (CommonName) that
              fetchmail expects on the server certificate.  A correctly  configured  server  will
              have  this  set  to  the host name by which it is reached, and by default fetchmail
              will expect as much. Use this option when the  CommonName  is  set  to  some  other
              value,  to avoid the "Server CommonName mismatch" warning, and only if the upstream
              server's operator cannot be made to use proper certificates.

       --sslfingerprint <fingerprint>
              (Keyword: sslfingerprint)
              Specify the fingerprint of the server key (an MD5 hash of the key)  in  hexadecimal
              notation with colons separating groups of two digits. The letter hex digits must be
              in upper case. This is the format that fetchmail uses  to  report  the  fingerprint
              when  an  SSL  connection  is  established.  When this is specified, fetchmail will
              compare the server key fingerprint with the given one, and the connection will fail
              if they do not match, regardless of the sslcertck setting. The connection will also
              fail if fetchmail cannot obtain an SSL certificate from the server.   This  can  be
              used  to  prevent  man-in-the-middle  attacks, but the finger print from the server
              must be obtained or verified over a secure channel, and certainly not over the same
              Internet connection that fetchmail would use.

              Using  this option will prevent printing certificate verification errors as long as
              --nosslcertck is in effect.

              To obtain the fingerprint of a certificate stored in the file cert.pem, try:

                   openssl x509 -in cert.pem -noout -md5 -fingerprint

              For details, see x509(1ssl).

   Delivery Control Options
       -S <hosts> | --smtphost <hosts>
              (Keyword: smtp[host])
              Specify a hunt list of hosts to forward mail to (one or  more  host  names,  comma-
              separated).  Hosts  are  tried  in list order; the first one that is up becomes the
              forwarding  target  for  the  current  run.   If  this  option  is  not  specified,
              'localhost'  is  used  as  the  default.   Each  host  name  may have a port number
              following the host name.  The port number is separated from  the  host  name  by  a
              slash; the default port is "smtp".  If you specify an absolute path name (beginning
              with a /), it will be interpreted as the name  of  a  UNIX  socket  accepting  LMTP
              connections (such as is supported by the Cyrus IMAP daemon) Example:

                   --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp

              This option can be used with ODMR, and will make fetchmail a relay between the ODMR
              server and SMTP or LMTP receiver.

              WARNING: if you use address numeric IP addresses here, be sure to use --smtpaddress
              or --smtpname (either of which see) with a valid SMTP address literal!

       --fetchdomains <hosts>
              (Keyword: fetchdomains)
              In  ETRN  or ODMR mode, this option specifies the list of domains the server should
              ship mail for once the connection is turned around.  The default is the FQDN of the
              machine running fetchmail.

       -D <domain> | --smtpaddress <domain>
              (Keyword: smtpaddress)
              Specify  the  domain  to be appended to addresses in RCPT TO lines shipped to SMTP.
              When this is  not  specified,  the  name  of  the  SMTP  server  (as  specified  by
              --smtphost) is used for SMTP/LMTP and 'localhost' is used for UNIX socket/BSMTP.

              NOTE: if you intend to use numeric addresses, or so-called address literals per the
              SMTP standard, write  them  in  proper  SMTP  syntax,  for  instance  --smtpaddress
              "[]" or --smtpaddress "[IPv6:2001:DB8::6]".

       --smtpname <user@domain>
              (Keyword: smtpname)
              Specify  the  domain  and  user  to  be  put in RCPT TO lines shipped to SMTP.  The
              default  user  is  the  current  local  user.  Please  also  see  the  NOTE   about
              --smtpaddress and address literals above.

       -Z <nnn> | --antispam <nnn[, nnn]...>
              (Keyword: antispam)
              Specifies  the  list  of  numeric SMTP errors that are to be interpreted as a spam-
              block response from the listener.  A value of -1 disables  this  option.   For  the
              command-line  option,  the  list  values  should be comma-separated.  Note that the
              antispam values only apply to "MAIL FROM" responses in the SMTP/LMTP dialogue,  but
              several  MTAs  (Postfix  in  its  default configuration, qmail) defer the anti-spam
              response code  until  after  the  RCPT  TO.  --antispam  does  not  work  in  these
              circumstances.  Also see --softbounce (default) and its inverse.

       -m <command> | --mda <command>
              (Keyword: mda)
              This  option  lets  fetchmail  use  a  Message or Local Delivery Agent (MDA or LDA)
              directly, rather than forward via SMTP or LMTP.

              To avoid losing mail, use this option only with MDAs like  maildrop  or  MTAs  like
              sendmail  that  exit  with a nonzero status on disk-full and other delivery errors;
              the nonzero status tells fetchmail that delivery failed and  prevents  the  message
              from being deleted on the server.

              If  fetchmail is running as root, it sets its user id while delivering mail through
              an MDA as  follows:   First,  the  FETCHMAILUSER,  LOGNAME,  and  USER  environment
              variables  are checked in this order. The value of the first variable from his list
              that is defined (even if it is empty!) is looked up in the system user database. If
              none  of  the  variables  is  defined,  fetchmail  will use the real user id it was
              started with. If one of the variables was defined, but the user stated there is not
              found, fetchmail continues running as root, without checking remaining variables on
              the list.  Practically,  this  means  that  if  you  run  fetchmail  as  root  (not
              recommended), it is most useful to define the FETCHMAILUSER environment variable to
              set the user that the MDA should run as. Some MDAs (such as maildrop) are  designed
              to  be  setuid  root  and  setuid  to  the  recipient's user id, so you do not lose
              functionality this way even when running fetchmail as unprivileged user.  Check the
              MDA's manual for details.

              Some  possible  MDAs  are  "/usr/sbin/sendmail  -i -f %F -- %T" (Note: some several
              older or vendor sendmail versions  mistake  --  for  an  address,  rather  than  an
              indicator  to  mark  the  end  of  the  option  arguments),  "/usr/bin/deliver" and
              "/usr/bin/maildrop -d %T".  Local delivery addresses will be inserted into the  MDA
              command  wherever  you place a %T; the mail message's From address will be inserted
              where you place an %F.

              Do NOT enclose the %F or %T string in single quotes!  For both %T and %F, fetchmail
              encloses  the addresses in single quotes ('), after removing any single quotes they
              may contain, before the MDA command is passed to the shell.

              Do NOT use an MDA invocation that dispatches on the  contents  of  To/Cc/Bcc,  like
              "sendmail  -i  -t"  or "qmail-inject", it will create mail loops and bring the just
              wrath of many postmasters down upon your head.  This is one of  the  most  frequent
              configuration errors!

              Also,  do  not  try to combine multidrop mode with an MDA such as maildrop that can
              only accept one address, unless your upstream stores one copy of  the  message  per
              recipient and transports the envelope recipient in a header; you will lose mail.

              The  well-known  procmail(1)  package  is very hard to configure properly, it has a
              very nasty "fall through to the  next  rule"  behavior  on  delivery  errors  (even
              temporary  ones, such as out of disk space if another user's mail daemon copies the
              mailbox around to purge old messages), so your  mail  will  end  up  in  the  wrong
              mailbox  sooner or later. The proper procmail configuration is outside the scope of
              this document. Using maildrop(1) is usually much easier, and many  users  find  the
              filter syntax used by maildrop easier to understand.

              Finally,  we  strongly  advise  that you do not use qmail-inject.  The command line
              interface is non-standard without providing benefits for typical use, and fetchmail
              makes  no attempts to accommodate qmail-inject's deviations from the standard. Some
              of qmail-inject's command-line and environment options are actually  dangerous  and
              can cause broken threads, non-detected duplicate messages and forwarding loops.

       --lmtp (Keyword: lmtp)
              Cause  delivery  via  LMTP (Local Mail Transfer Protocol).  A service host and port
              must be explicitly specified on each host in the smtphost hunt list (see above)  if
              this option is selected; the default port 25 will (in accordance with RFC 2033) not
              be accepted.

       --bsmtp <filename>
              (Keyword: bsmtp)
              Append fetched mail to a BSMTP file.  This simply contains the SMTP  commands  that
              would  normally  be  generated  by  fetchmail when passing mail to an SMTP listener

              An argument of '-' causes the SMTP batch to be written to standard output, which is
              of  limited  use:  this only makes sense for debugging, because fetchmail's regular
              output is interspersed on the same channel,  so  this  is  not  suitable  for  mail
              delivery. This special mode may be removed in a later release.

              Note  that  fetchmail's  reconstruction  of  MAIL  FROM  and  RCPT  TO lines is not
              guaranteed correct; the caveats discussed under THE  USE  AND  ABUSE  OF  MULTIDROP
              MAILBOXES below apply.  This mode has precedence before --mda and SMTP/LMTP.

       --bad-header {reject|accept}
              (Keyword: bad-header; since v6.3.15)
              Specify how fetchmail is supposed to treat messages with bad headers, i.e., headers
              with bad syntax. Traditionally, fetchmail has  rejected  such  messages,  but  some
              distributors  modified  fetchmail to accept them. You can now configure fetchmail's
              behaviour per server.

   Resource Limit Control Options
       -l <maxbytes> | --limit <maxbytes>
              (Keyword: limit)
              Takes a maximum octet size argument, where 0 is the default and  also  the  special
              value  designating "no limit".  If nonzero, messages larger than this size will not
              be fetched and will be left on the server (in  foreground  sessions,  the  progress
              messages  will  note that they are "oversized").  If the fetch protocol permits (in
              particular, under IMAP or POP3 without the fetchall option) the message will not be
              marked seen.

              An  explicit  --limit  of 0 overrides any limits set in your run control file. This
              option is intended for  those  needing  to  strictly  control  fetch  time  due  to
              expensive and variable phone rates.

              Combined  with --limitflush, it can be used to delete oversized messages waiting on
              a server.  In daemon mode, oversize notifications are mailed to  the  calling  user
              (see the --warnings option). This option does not work with ETRN or ODMR.

       -w <interval> | --warnings <interval>
              (Keyword: warnings)
              Takes  an  interval  in  seconds.  When you call fetchmail with a 'limit' option in
              daemon mode, this controls the interval at which warnings about oversized  messages
              are  mailed to the calling user (or the user specified by the 'postmaster' option).
              One such notification is always mailed at the  end  of  the  first  poll  that  the
              oversized  message  is  detected.   Thereafter, re-notification is suppressed until
              after the warning interval elapses (it will take place at  the  end  of  the  first
              following poll).

       -b <count> | --batchlimit <count>
              (Keyword: batchlimit)
              Specify  the  maximum  number  of messages that will be shipped to an SMTP listener
              before the connection is deliberately torn down and rebuilt (defaults to 0, meaning
              no  limit).   An  explicit  --batchlimit  of 0 overrides any limits set in your run
              control  file.   While  sendmail(8)  normally  initiates  delivery  of  a   message
              immediately  after receiving the message terminator, some SMTP listeners are not so
              prompt.  MTAs like smail(8) may wait till the  delivery  socket  is  shut  down  to
              deliver.   This may produce annoying delays when fetchmail is processing very large
              batches.  Setting the batch limit to some nonzero size will prevent  these  delays.
              This option does not work with ETRN or ODMR.

       -B <number> | --fetchlimit <number>
              (Keyword: fetchlimit)
              Limit  the  number  of  messages accepted from a given server in a single poll.  By
              default there is no limit. An explicit --fetchlimit of 0 overrides any  limits  set
              in your run control file.  This option does not work with ETRN or ODMR.

       --fetchsizelimit <number>
              (Keyword: fetchsizelimit)
              Limit  the  number  of  sizes  of messages accepted from a given server in a single
              transaction.  This option is useful in reducing the delay in downloading the  first
              mail  when  there are too many mails in the mailbox.  By default, the limit is 100.
              If set to 0, sizes of all messages are downloaded at the start.  This  option  does
              not work with ETRN or ODMR.  For POP3, the only valid non-zero value is 1.

       --fastuidl <number>
              (Keyword: fastuidl)
              Do a binary instead of linear search for the first unseen UID. Binary search avoids
              downloading the UIDs of all mails. This saves  time  (especially  in  daemon  mode)
              where  downloading  the  same set of UIDs in each poll is a waste of bandwidth. The
              number 'n' indicates how rarely a linear search should be  done.  In  daemon  mode,
              linear  search  is  used  once followed by binary searches in 'n-1' polls if 'n' is
              greater than 1; binary search is always used if 'n' is 1; linear search  is  always
              used  if 'n' is 0. In non-daemon mode, binary search is used if 'n' is 1; otherwise
              linear search is used. The default value of 'n' is 4.  This option works with  POP3

       -e <count> | --expunge <count>
              (Keyword: expunge)
              Arrange  for  deletions  to  be made final after a given number of messages.  Under
              POP2 or POP3, fetchmail cannot make deletions final without sending QUIT and ending
              the  session  --  with  this  option on, fetchmail will break a long mail retrieval
              session into multiple sub-sessions, sending QUIT after each sub-session. This is  a
              good  defense  against  line drops on POP3 servers.  Under IMAP, fetchmail normally
              issues an EXPUNGE command after each deletion in order to force the deletion to  be
              done  immediately.   This is safest when your connection to the server is flaky and
              expensive, as it avoids re-sending duplicate mail after a line  hit.   However,  on
              large mailboxes the overhead of re-indexing after every message can slam the server
              pretty hard, so if your connection is reliable it  is  good  to  do  expunges  less
              frequently.   Also  note  that  some servers enforce a delay of a few seconds after
              each quit, so fetchmail may not be able to get back in immediately after an expunge
              -- you may see "lock busy" errors if this happens. If you specify this option to an
              integer N, it tells fetchmail to only issue  expunges  on  every  Nth  delete.   An
              argument  of  zero suppresses expunges entirely (so no expunges at all will be done
              until the end of run).  This option does not work with ETRN or ODMR.

   Authentication Options
       -u <name> | --user <name> | --username <name>
              (Keyword: user[name])
              Specifies the user identification to be used when logging in to  the  mail  server.
              The appropriate user identification is both server and user-dependent.  The default
              is your login name on the client machine  that  is  running  fetchmail.   See  USER
              AUTHENTICATION below for a complete description.

       -I <specification> | --interface <specification>
              (Keyword: interface)
              Require  that a specific interface device be up and have a specific local or remote
              IPv4 (IPv6 is not supported by this option yet) address (or range) before  polling.
              Frequently   fetchmail   is  used  over  a  transient  point-to-point  TCP/IP  link
              established directly to a mail server via SLIP or PPP.  That is a relatively secure
              channel.   But  when  other  TCP/IP routes to the mail server exist (e.g., when the
              link is connected  to  an  alternate  ISP),  your  username  and  password  may  be
              vulnerable  to  snooping (especially when daemon mode automatically polls for mail,
              shipping a clear password over the net at predictable intervals).  The  --interface
              option  may  be  used to prevent this.  When the specified link is not up or is not
              connected to a matching IP address, polling will be skipped.  The format is:


              The field before the first slash is the interface name (i.e., sl0, ppp0 etc.).  The
              field  before  the  second slash is the acceptable IP address.  The field after the
              second slash is a mask which specifies a range of IP addresses to  accept.   If  no
              mask  is present is assumed (i.e., an exact match).  This option is
              currently only supported under Linux and FreeBSD. Please see  the  monitor  section
              for below for FreeBSD specific information.

              Note that this option may be removed from a future fetchmail version.

       -M <interface> | --monitor <interface>
              (Keyword: monitor)
              Daemon  mode  can  cause transient links which are automatically taken down after a
              period of inactivity (e.g., PPP links) to  remain  up  indefinitely.   This  option
              identifies a system TCP/IP interface to be monitored for activity.  After each poll
              interval, if the link is up but no other activity has occurred on  the  link,  then
              the  poll  will  be  skipped.  However, when fetchmail is woken up by a signal, the
              monitor check is skipped and the poll goes through unconditionally.  This option is
              currently  only  supported  under Linux and FreeBSD.  For the monitor and interface
              options to work for non root users under FreeBSD,  the  fetchmail  binary  must  be
              installed  setgid kmem.  This would be a security hole, but fetchmail runs with the
              effective GID set to that of the kmem group  only  when  interface  data  is  being

              Note that this option may be removed from a future fetchmail version.

       --auth <type>
              (Keyword: auth[enticate])
              This  option permits you to specify an authentication type (see USER AUTHENTICATION
              below for details).  The possible values are any, password,  kerberos_v5,  kerberos
              (or,  for  excruciating  exactness,  kerberos_v4), gssapi, cram-md5, otp, ntlm, msn
              (only for POP3),  external  (only  IMAP)  and  ssh.   When  any  (the  default)  is
              specified,  fetchmail tries first methods that do not require a password (EXTERNAL,
              GSSAPI, KERBEROS IV, KERBEROS 5); then it looks for methods that mask your password
              (CRAM-MD5,  NTLM,  X-OTP  - note that MSN is only supported for POP3, but not auto-
              probed); and only if the server does not support any of those  will  it  ship  your
              password  unencrypted.   Other  values  may be used to force various authentication
              methods: ssh suppresses authentication and is thus useful for IMAP PREAUTH (if  you
              are  using a secure --plugin, for instance, a properly configured ssh, you may also
              need to set --sslproto '' or,  in  the  rcfile,  sslproto '',  in  order  to  avoid
              fetchmail  negotiating  STARTTLS over SSH).  external suppresses authentication and
              is thus useful for IMAP EXTERNAL.  Any value other than password,  cram-md5,  ntlm,
              msn  or otp suppresses fetchmail's normal inquiry for a password.  Specify ssh when
              you are using an end-to-end secure connection such as an ssh tunnel (in  this  case
              you  may  also want to specify --sslproto '', which see); specify external when you
              use TLS with client authentication and specify gssapi or  kerberos_v4  if  you  are
              using  a  protocol  variant  that  employs  GSSAPI  or  K4.  Choosing KPOP protocol
              automatically selects Kerberos authentication.  This  option  does  not  work  with
              ETRN.   GSSAPI  service names are in line with RFC-2743 and IANA registrations, see
              Generic Security Service  Application  Program  Interface  (GSSAPI)/Kerberos/Simple
              Authentication      and      Security      Layer      (SASL)      Service     Names

   Miscellaneous Options
       -f <pathname> | --fetchmailrc <pathname>
              Specify a non-default name for the ~/.fetchmailrc run control file.   The  pathname
              argument  must be either "-" (a single dash, meaning to read the configuration from
              standard input) or a filename.  Unless the --version option is  also  on,  a  named
              file argument must have permissions no more open than 0700 (u=rwx,g=,o=) or else be

       -i <pathname> | --idfile <pathname>
              (Keyword: idfile)
              Specify an alternate name for the .fetchids file used to save message  UIDs.  NOTE:
              since  fetchmail  6.3.0,  write  access  to  the directory containing the idfile is
              required, as fetchmail writes a temporary file and renames it into the place of the
              real  idfile  only if the temporary file has been written successfully. This avoids
              the truncation of idfiles when running out of disk space.

       --pidfile <pathname>
              (Keyword: pidfile; since fetchmail v6.3.4)
              Override the default location of the  PID  file  that  is  used  as  a  lock  file.
              Default:   see  "ENVIRONMENT"  below.  Note  that  many  places  in  the  code  and
              documentation, the term "lock file" is used.  This file contains the process ID  of
              the  running  fetchmail  on the first line and potentially the daemon interval on a
              second line.

       -n | --norewrite
              (Keyword: no rewrite)
              Normally, fetchmail edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To)
              in  fetched  mail  so  that  any  mail IDs local to the server are expanded to full
              addresses (@ and the mail server host name are appended).  This enables replies  on
              the  client  to  get  addressed  correctly  (otherwise your mailer might think they
              should be addressed to local users on the client machine!).  This  option  disables
              the  rewrite.   (This  option  is  provided to pacify people who are paranoid about
              having an MTA edit mail headers and want to know they can prevent  it,  but  it  is
              generally  not a good idea to actually turn off rewrite.)  When using ETRN or ODMR,
              the rewrite option is ineffective.

       -E <line> | --envelope <line>
              (Keyword: envelope; Multidrop only)
              In the configuration file, an enhanced syntax is used:
              envelope [<count>] <line>

              This option changes the header fetchmail assumes will carry a copy  of  the  mail's
              envelope address.  Normally this is 'X-Envelope-To'.  Other typically found headers
              to carry envelope information are 'X-Original-To' and 'Delivered-To'.   Now,  since
              these  headers  are  not  standardized,  practice  varies.  See  the  discussion of
              multidrop address handling below.  As a special case, 'envelope "Received"' enables
              parsing  of  sendmail-style  Received  lines.  This is the default, but discouraged
              because it is not fully reliable.

              Note that fetchmail expects the Received-line to be in a specific format:  It  must
              contain  "by  host for address", where host must match one of the mail server names
              that fetchmail recognizes for the account in question.

              The optional count argument (only available in the configuration  file)  determines
              how many header lines of this kind are skipped. A count of 1 means: skip the first,
              take the second. A count of 2 means: skip the first and second, take the third, and
              so on.

       -Q <prefix> | --qvirtual <prefix>
              (Keyword: qvirtual; Multidrop only)
              The  string prefix assigned to this option will be removed from the user name found
              in the header specified with the  envelope  option  (before  doing  multidrop  name
              mapping or localdomain checking, if either is applicable). This option is useful if
              you are using fetchmail to collect the mail for an entire domain and your  ISP  (or
              your mail redirection provider) is using qmail.  One of the basic features of qmail
              is the Delivered-To: message header.  Whenever qmail delivers a message to a  local
              mailbox  it puts the username and host name of the envelope recipient on this line.
              The major reason for this is to prevent mail loops.  To set up qmail to batch  mail
              for  a  disconnected  site the ISP-mailhost will have normally put that site in its
              'Virtualhosts' control file so it will add a prefix to all mail addresses for  this
              site.  This  results  in  mail sent to '' having a
              Delivered-To: line of the form:


              The ISP can make the 'mbox-userstr-' prefix  anything  they  choose  but  a  string
              matching   the   user   host  name  is  likely.   By  using  the  option  'envelope
              Delivered-To:' you can make  fetchmail  reliably  identify  the  original  envelope
              recipient,  but  you  have  to  strip  the 'mbox-userstr-' prefix to deliver to the
              correct user.  This is what this option is for.

              Parse the ~/.fetchmailrc file, interpret any command-line  options  specified,  and
              dump a configuration report to standard output.  The configuration report is a data
              structure assignment in the language Python.  This option is meant to be used  with
              an interactive ~/.fetchmailrc editor like fetchmailconf, written in Python.

       -y | --yydebug
              Enables parser debugging, this option is meant to be used by developers only.

   Removed Options
       -T | --netsec
              Removed  before  version 6.3.0, the required underlying inet6_apps library had been
              discontinued and is no longer available.


       All modes except ETRN require authentication of the client to  the  server.   Normal  user
       authentication in fetchmail is very much like the authentication mechanism of ftp(1).  The
       correct user-id and password depend upon  the  underlying  security  system  at  the  mail

       If  the  mail  server  is  a Unix machine on which you have an ordinary user account, your
       regular login name and password are used with fetchmail.  If you use the same  login  name
       on  both  the server and the client machines, you needn't worry about specifying a user-id
       with the -u option -- the default behavior is to use your login name on the client machine
       as  the  user-id  on  the server machine.  If you use a different login name on the server
       machine, specify that login name with the -u option.  E.g., if your login name is 'jsmith'
       on a machine named 'mailgrunt', you would start fetchmail as follows:

              fetchmail -u jsmith mailgrunt

       The  default  behavior  of fetchmail is to prompt you for your mail server password before
       the connection is established.  This is the safest way to use fetchmail and  ensures  that
       your  password  will  not  be  compromised.   You  may  also specify your password in your
       ~/.fetchmailrc file.  This is convenient when using  fetchmail  in  daemon  mode  or  with

   Using netrc files
       If   you  do  not  specify  a  password,  and  fetchmail  cannot  extract  one  from  your
       ~/.fetchmailrc file, it will look for a  ~/.netrc  file  in  your  home  directory  before
       requesting  one interactively; if an entry matching the mail server is found in that file,
       the password will be used.  Fetchmail first looks for a match on poll name;  if  it  finds
       none,  it  checks  for  a  match  on via name.  See the ftp(1) man page for details of the
       syntax of the ~/.netrc file.  To show a practical example, a .netrc might look like this:

              login joe
              password topsecret

       You can repeat this block with different user information if you need to provide more than
       one password.

       This  feature  may  allow  you  to avoid duplicating password information in more than one

       On mail servers that do not provide ordinary user accounts, your user-id and password  are
       usually  assigned  by the server administrator when you apply for a mailbox on the server.
       Contact your server administrator if you do not know the correct user-id and password  for
       your mailbox account.

   Secure Socket Layers (SSL) and Transport Layer Security (TLS)
       All  retrieval protocols can use SSL or TLS wrapping for the transport. Additionally, POP3
       and IMAP retrieval can also negotiate SSL/TLS by means of STARTTLS (or STLS).

       You can access TLS-encrypted services by specifying the options starting with --ssl,  such
       as  --ssl,  --sslproto,  --sslcertck,  and  others.   You  can  also  do  this  using  the
       corresponding user options in the .fetchmailrc file.  Some  services,  such  as  POP3  and
       IMAP,  have  different  well  known  ports  defined  for  the SSL encrypted services.  The
       encrypted ports will be selected automatically when SSL is enabled and no explicit port is
       specified.    Also,  the  --sslcertck  command  line  or sslcertck run control file option
       should be used to force strict certificate checking with older fetchmail  versions  -  see

       If TLS or SSL is not configured, fetchmail will usually still try to use STARTTLS somewhat
       opportunistically. In practice, is it still mandatory because  --sslcertck  is  a  default
       setting and implicitly requires STARTTLS.

       STARTTLS  can  be  enforced  by using --sslproto auto and defeated by using --sslproto ''.
       STARTTLS connections use the same port as the unencrypted  version  of  the  protocol  and
       negotiate  TLS  via special command. The --sslcertck command line or sslcertck run control
       file option should be used to force strict certificate checking - see below.

       --sslcertck is recommended: When connecting to an SSL or TLS encrypted server, the  server
       presents a certificate to the client for validation.  The certificate is checked to verify
       that the common name in the certificate matches the name of the server being contacted and
       that  the  effective and expiration dates in the certificate indicate that it is currently
       valid.  If any of these checks fail, a warning message  is  printed,  but  the  connection
       continues.   The  server certificate does not need to be signed by any specific Certifying
       Authority and may be a "self-signed" certificate. If the --sslcertck command  line  option
       or sslcertck run control file option is used, fetchmail will instead abort if any of these
       checks fail, because it must assume that there  is  a  man-in-the-middle  attack  in  this
       scenario,  hence  fetchmail  must not expose clear-text passwords. Use of the sslcertck or
       --sslcertck option is therefore advised; it has become the default in fetchmail 6.4.0.

       Some SSL encrypted servers may request a client side certificate.  A  client  side  public
       SSL  certificate  and  private  SSL key may be specified.  If requested by the server, the
       client certificate is sent to the server for validation.  Some servers may require a valid
       client  certificate  and may refuse connections if a certificate is not provided or if the
       certificate is not valid.  Some servers may require client side certificates be signed  by
       a recognized Certifying Authority.  The format for the key files and the certificate files
       is that required by the underlying SSL libraries (OpenSSL in the general case).

       A word of care about the use of SSL: While above mentioned setup with  self-signed  server
       certificates retrieved over the wires can protect you from a passive eavesdropper, it does
       not help against an active attacker.  It  is  clearly  an  improvement  over  sending  the
       passwords  in  clear, but you should be aware that a man-in-the-middle attack is trivially
       possible (in particular with tools such as dsniff  ⟨⟩).
       Use of strict certificate checking with a certification authority recognized by server and
       client, or perhaps of an SSH tunnel (see below for some examples)  is  preferable  if  you
       care seriously about the security of your mailbox and passwords.


       Early  versions  of  POP3  (RFC1081,  RFC1225)  supported  a  crude  form  of  independent
       authentication using the .rhosts file on the mail server side.  Under this RPOP variant, a
       fixed  per-user  ID  equivalent  to a password was sent in clear over a link to a reserved
       port, with the command RPOP rather than PASS to alert the server that it should do special
       checking.   RPOP  is  supported  by fetchmail (you can specify 'protocol RPOP' to have the
       program send 'RPOP' rather than 'PASS') but its use is strongly discouraged,  and  support
       will be removed from a future fetchmail version.  This facility was vulnerable to spoofing
       and was withdrawn in RFC1460.

       RFC1460 introduced APOP authentication.  In this variant of POP3,  you  register  an  APOP
       password  on  your  server  host  (on  some  servers,  the  program  to  do this is called
       popauth(8)).  You put the same password in your ~/.fetchmailrc file.  Each time  fetchmail
       logs in, it sends an MD5 hash of your password and the server greeting time to the server,
       which can verify it by checking its authorization database.

       Note that APOP is no longer considered resistant against man-in-the-middle attacks.

   RETR or TOP
       fetchmail makes some efforts to make the server believe messages had not  been  retrieved,
       by  using  the  TOP  command with a large number of lines when possible.  TOP is a command
       that retrieves the full header and a fetchmail-specified  amount  of  body  lines.  It  is
       optional  and therefore not implemented by all servers, and some are known to implement it
       improperly. On many servers however, the RETR command which  retrieves  the  full  message
       with header and body, sets the "seen" flag (for instance, in a web interface), whereas the
       TOP command does not do that.

       fetchmail will always use the RETR command if "fetchall" is set.  fetchmail will also  use
       the  RETR  command  if "keep" is set and "uidl" is unset.  Finally, fetchmail will use the
       RETR command on Maillennium POP3/PROXY servers (used by Comcast) to avoid a deliberate TOP
       misinterpretation in this server that causes message corruption.

       In  all  other  cases,  fetchmail  will  use  the TOP command. This implies that in "keep"
       setups, "uidl" must be set if "TOP" is desired.

       Note that this description is true for the current version of fetchmail, but the  behavior
       may  change  in  future  versions.  In  particular,  fetchmail may prefer the RETR command
       because the TOP command causes much grief on some servers and is only optional.


       If your fetchmail was built with Kerberos support and you specify Kerberos  authentication
       (either  with  --auth  or the .fetchmailrc option authenticate kerberos_v4) it will try to
       get a Kerberos ticket from the mail server at the start of each query.   Note:  if  either
       the pollname or via name is 'hesiod', fetchmail will try to use Hesiod to look up the mail

       If you use POP3 or IMAP with GSSAPI authentication, fetchmail will expect  the  server  to
       have  RFC1731-  or  RFC1734-conforming GSSAPI capability, and will use it.  Currently this
       has only been tested over Kerberos 5, so you  are  expected  to  already  have  a  ticket-
       granting  ticket.  You  may  pass  a username different from your principal name using the
       standard --user command or by the .fetchmailrc option user.

       If your IMAP daemon returns the PREAUTH response in  its  greeting  line,  fetchmail  will
       notice  this  and  skip  the normal authentication step.  This can be useful, e.g., if you
       start imapd explicitly using ssh.  In this case you can declare the  authentication  value
       'ssh'  on that site entry to stop .fetchmail from asking you for a password when it starts

       If you use client authentication with TLS1 and your IMAP daemon returns the  AUTH=EXTERNAL
       response, fetchmail will notice this and will use the authentication shortcut and will not
       send the passphrase. In this case you can declare the authentication value 'external'
        on that site to stop fetchmail from asking you for a password when it starts up.

       If you are using POP3, and the server issues a one-time-password challenge  conforming  to
       RFC1938,  fetchmail  will  use  your  password  as  a pass phrase to generate the required
       response. This avoids sending secrets over the net unencrypted.

       Compuserve's RPA authentication is supported. If you compile  in  the  support,  fetchmail
       will try to perform an RPA pass-phrase authentication instead of sending over the password
       unencrypted if it detects "" in the host name.

       If you are using IMAP, Microsoft's NTLM authentication (used  by  Microsoft  Exchange)  is
       supported.  If  you  compile  in  the  support,  fetchmail  will  try  to  perform an NTLM
       authentication (instead of sending over the  password  unencrypted)  whenever  the  server
       returns  AUTH=NTLM in its capability response. Specify a user option value that looks like
       'user@domain': the part to the left of the @ will be passed as the username and  the  part
       to the right as the NTLM domain.

       fetchmail also supports authentication to the ESMTP server on the client side according to
       RFC 2554.  You can specify a name/password pair to be used with the  keywords  'esmtpname'
       and 'esmtppassword'; the former defaults to the username of the calling user.


   Introducing the daemon mode
       In  daemon mode, fetchmail puts itself into the background and runs forever, querying each
       specified host and then sleeping for a given polling interval.

   Starting the daemon mode
       There are several ways to make fetchmail  work  in  daemon  mode.  On  the  command  line,
       --daemon <interval>  or  -d <interval>  option  runs  fetchmail  in daemon mode.  You must
       specify a numeric argument which is a polling interval (time to wait  after  completing  a
       whole  poll  cycle  with  the last server and before starting the next poll cycle with the
       first server) in seconds.

       Example: simply invoking

              fetchmail -d 900

       will, therefore, poll all the hosts described in your ~/.fetchmailrc  file  (except  those
       explicitly  excluded  with  the  'skip'  verb) a bit less often than once every 15 minutes
       (exactly: 15 minutes + time that the poll takes).

       It is also possible to set a polling  interval  in  your  ~/.fetchmailrc  file  by  saying
       'set daemon <interval>',  where  <interval>  is  an  integer number of seconds.  If you do
       this, fetchmail will always start in daemon mode unless you override it with the  command-
       line option --daemon 0 or -d0.

       Only  one  daemon  process is permitted per user; in daemon mode, fetchmail sets up a per-
       user lock file to guarantee this.  (You  can  however  cheat  and  set  the  FETCHMAILHOME
       environment variable to overcome this setting, but in that case, it is your responsibility
       to make sure you are not polling the same server with two processes at the same time.)

   Awakening the background daemon
       Normally, calling fetchmail with a daemon in the background sends a wake-up signal to  the
       daemon  and  quits  without  output. The background daemon then starts its next poll cycle
       immediately.  The wake-up signal, SIGUSR1, can also be sent manually. The  wake-up  action
       also  clears  any  'wedged'  flags  indicating  that connections have wedged due to failed
       authentication or multiple timeouts.

   Terminating the background daemon
       The option -q or --quit will kill a running daemon process instead of  waking  it  up  (if
       there  is  no such process, fetchmail will notify you).  If the --quit option appears last
       on the command line, fetchmail will  kill  the  running  daemon  process  and  then  quit.
       Otherwise,  fetchmail  will  first kill a running daemon process and then continue running
       with the other options.

   Useful options for daemon mode
       The -L <filename> or --logfile <filename> option (keyword: set logfile) is only  effective
       when  fetchmail  is  detached  and in daemon mode. Note that the logfile must exist before
       fetchmail is run, you can use the touch(1) command with the filename as its sole  argument
       to create it.
       This  option  allows  you to redirect status messages into a specified logfile (follow the
       option with the logfile name).  The logfile is opened for append, so previous messages are
       not  deleted.   This is primarily useful for debugging configurations. Note that fetchmail
       does not detect if the logfile is rotated, the logfile is only opened once when  fetchmail
       starts. You need to restart fetchmail after rotating the logfile and before compressing it
       (if applicable).

       The --syslog option (keyword: set syslog) allows you to redirect status and error messages
       emitted  to  the  syslog(3) system daemon if available.  Messages are logged with an id of
       fetchmail, the facility LOG_MAIL, and priorities LOG_ERR,  LOG_ALERT  or  LOG_INFO.   This
       option  is intended for logging status and error messages which indicate the status of the
       daemon and the results while fetching mail from the server(s).  Error messages for command
       line  options  and  parsing  the  .fetchmailrc file are still written to stderr, or to the
       specified log file.  The --nosyslog option turns off use  of  syslog(3),  assuming  it  is
       turned  on  in the ~/.fetchmailrc file.  This option is overridden, in certain situations,
       by --logfile (which see).

       The -N or --nodetach option suppresses backgrounding and detachment of the daemon  process
       from  its  control  terminal.   This is useful for debugging or when fetchmail runs as the
       child of a supervisor process such as init(8) or Gerrit Pape's runit(8).  Note  that  this
       also causes the logfile option to be ignored.

       Note that while running in daemon mode polling a POP2 or IMAP2bis server, transient errors
       (such as DNS failures or sendmail delivery refusals) may force the fetchall option on  for
       the duration of the next polling cycle.  This is a robustness feature.  It means that if a
       message is fetched (and thus marked seen by the mail server) but not delivered locally due
       to  some  transient  error,  it  will be re-fetched during the next poll cycle.  (The IMAP
       logic does not delete messages until they are delivered, so this problem does not arise.)

       If you touch or change the ~/.fetchmailrc file while fetchmail is running in daemon  mode,
       this  will  be  detected  at  the  beginning  of  the  next  poll  cycle.   When a changed
       ~/.fetchmailrc is detected, fetchmail rereads it and restarts from scratch (using exec(2);
       no  state  information  is retained in the new instance).  Note that if fetchmail needs to
       query for passwords, of that if you  break  the  ~/.fetchmailrc  file's  syntax,  the  new
       instance will softly and silently vanish away on startup.


       The  --postmaster  <name>  option  (keyword:  set  postmaster)  specifies  the last-resort
       username to which multidrop mail is to be forwarded if no matching local recipient can  be
       found.  It  is  also  used as destination of undeliverable mail if the 'bouncemail' global
       option is off and additionally for spam-blocked mail if the 'bouncemail' global option  is
       off and the 'spambounce' global option is on. This option defaults to the user who invoked
       fetchmail.  If the invoking user is root, then the default of  this  option  is  the  user
       'postmaster'.   Setting postmaster to the empty string causes such mail as described above
       to be discarded - this however is usually a bad idea.  See also  the  description  of  the
       'FETCHMAILUSER' environment variable in the ENVIRONMENT section below.

       The --nobounce behaves like the "set no bouncemail" global option, which see.

       The  --invisible  option  (keyword:  set  invisible)  tries  to  make fetchmail invisible.
       Normally, fetchmail behaves like any other MTA would -- it  generates  a  Received  header
       into  each message describing its place in the chain of transmission, and tells the MTA it
       forwards to that the mail came from the machine fetchmail itself is running  on.   If  the
       invisible option is on, the Received header is suppressed and fetchmail tries to spoof the
       MTA it forwards to into thinking it came directly from the mail server host.

       The --showdots option (keyword: set showdots) forces fetchmail to show progress dots  even
       if  the  output  goes  to a file or fetchmail is not in verbose mode.  Fetchmail shows the
       dots by default when run in --verbose mode and output goes  to  console.  This  option  is
       ignored in --silent mode.

       By  specifying  the  --tracepolls  option, you can ask fetchmail to add information to the
       Received header on the form "polling {label} account {user}", where {label} is the account
       label  (from  the  specified  rcfile,  normally ~/.fetchmailrc) and {user} is the username
       which is used to log on to the mail server. This header can  be  used  to  make  filtering
       email  where  no  useful  header information is available and you want mail from different
       accounts sorted into different mailboxes (this could, for example, occur if  you  have  an
       account  on  the  same server running a mailing list, and are subscribed to the list using
       that account). The default is not adding any such header.  In .fetchmailrc, this is called


       The  protocols  fetchmail uses to talk to mail servers are next to bulletproof.  In normal
       operation forwarding to port 25, no message is ever deleted (or even marked for  deletion)
       on  the host until the SMTP listener on the client side has acknowledged to fetchmail that
       the message has been either accepted for delivery or rejected due to a spam block.

       When forwarding to an MDA, however, there is more possibility of  error.   Some  MDAs  are
       'safe'  and  reliably  return  a  nonzero  status  on  any delivery error, even one due to
       temporary resource limits.  The maildrop(1) program is like this;  so  are  most  programs
       designed  as mail transport agents, such as sendmail(1), including the sendmail wrapper of
       Postfix and exim(1).  These programs give back a reliable positive acknowledgement and can
       be  used with the mda option with no risk of mail loss.  Unsafe MDAs, though, may return 0
       even on delivery failure.  If this happens, you will lose mail.

       The normal mode of fetchmail is to try to download only 'new' messages, leaving  untouched
       (and  undeleted)  messages you have already read directly on the server (or fetched with a
       previous fetchmail --keep).  But you may find that messages you have already read  on  the
       server  are  being  fetched  (and  deleted) even when you do not specify --all.  There are
       several reasons this can happen.

       One could be that you are using POP2.  The POP2 protocol  includes  no  representation  of
       'new'  or  'old'  state  in  messages, so fetchmail must treat all messages as new all the
       time.  But POP2 is obsolete, so this is unlikely.

       A potential POP3 problem might be servers that insert messages in the middle of  mailboxes
       (some  VMS  implementations  of  mail are rumored to do this).  The fetchmail code assumes
       that new messages are appended to the end of the mailbox; when this is  not  true  it  may
       treat some old messages as new and vice versa.  Using UIDL whilst setting fastuidl 0 might
       fix this, otherwise, consider switching to IMAP.

       Yet another POP3 problem is that if they cannot make temporary files in  the  user's  home
       directory, some POP3 servers will hand back an undocumented response that causes fetchmail
       to spuriously report "No mail".

       The IMAP code uses the presence or absence of the server flag \Seen to decide  whether  or
       not  a  message  is  new.   This  is not the right thing to do, fetchmail should check the
       UIDVALIDITY and use UID, but it does not do that yet. Under Unix, it counts on  your  IMAP
       server to notice the BSD-style Status flags set by mail user agents and set the \Seen flag
       from them when appropriate.  All Unix IMAP servers we know of do this, though  it  is  not
       specified  by  the  IMAP  RFCs.  If you ever trip over a server that does not, the symptom
       will be that messages you have already read on your host will look new to the server.   In
       this  (unlikely)  case,  only  messages  you  fetched  with  fetchmail --keep will be both
       undeleted and marked old.

       In ETRN and ODMR modes, fetchmail does not actually retrieve messages;  instead,  it  asks
       the  server's  SMTP  listener to start a queue flush to the client via SMTP.  Therefore it
       sends only undelivered messages.


       Many SMTP listeners allow administrators to set up 'spam filters' that  block  unsolicited
       email  from  specified  domains.  A MAIL FROM or DATA line that triggers this feature will
       elicit an SMTP response which (unfortunately) varies according to the listener.

       Newer versions of sendmail return an error code of 571.

       According to RFC2821, the correct thing to return in  this  situation  is  550  "Requested
       action  not  taken:  mailbox  unavailable"  (the  draft adds "[E.g., mailbox not found, no
       access, or command rejected for policy reasons].").

       Older versions of the exim MTA return 501 "Syntax error in parameters or arguments".

       The postfix MTA runs 554 as an antispam response.

       Zmailer may reject code with a 500 response (followed by  an  enhanced  status  code  that
       contains more information).

       Return  codes which fetchmail treats as antispam responses and discards the message can be
       set with the 'antispam' option.  This is one of the only three  circumstance  under  which
       fetchmail  ever  discards mail (the others are the 552 and 553 errors described below, and
       the suppression of multi-dropped messages with a message-ID already seen).

       If fetchmail is fetching from an IMAP server, the antispam response will be  detected  and
       the  message rejected immediately after the headers have been fetched, without reading the
       message body.  Thus, you will not pay for downloading spam message bodies.

       By default, the list of antispam responses is empty.

       If  the  spambounce  global  option  is  on,  mail  that  is  spam-blocked   triggers   an
       RFC1892/RFC1894  bounce  message  informing the originator that we do not accept mail from
       it. See also BUGS.


       Besides the spam-blocking described above, fetchmail takes special actions — that  may  be
       modified by the --softbounce option — on the following SMTP/ESMTP error response codes

       452 (insufficient system storage)
            Leave the message in the server mailbox for later retrieval.

       552 (message exceeds fixed maximum message size)
            Delete the message from the server.  Send bounce-mail to the originator.

       553 (invalid sending domain)
            Delete  the  message  from  the  server.   Do not even try to send bounce-mail to the

       Other errors greater or equal to 500 trigger bounce mail back to  the  originator,  unless
       suppressed by --softbounce. See also BUGS.


       The  preferred  way  to  set  up  fetchmail  is  to write a .fetchmailrc file in your home
       directory (you may do this directly, with a text editor, or indirectly via fetchmailconf).
       When  there  is  a  conflict  between the command-line arguments and the arguments in this
       file, the command-line arguments take precedence.

       To protect the security of your passwords, your ~/.fetchmailrc may not normally have  more
       than  0700  (u=rwx,g=,o=)  permissions;  fetchmail  will complain and exit otherwise (this
       check is suppressed when --version is on).

       You may read the .fetchmailrc file as a list of commands to be executed when fetchmail  is
       called with no arguments.

   Run Control Syntax
       Comments  begin  with  a  '#'  and extend through the end of the line.  Otherwise the file
       consists of a series of server entries or  global  option  statements  in  a  free-format,
       token-oriented syntax.

       There are four kinds of tokens: grammar keywords, numbers (i.e., decimal digit sequences),
       unquoted strings, and quoted strings.  A quoted string is bounded by double quotes and may
       contain  whitespace (and quoted digits are treated as a string).  Note that quoted strings
       will also contain line feed characters if they run across two or more  lines,  unless  you
       use a backslash to join lines (see below).  An unquoted string is any whitespace-delimited
       token that is neither numeric, string quoted nor contains the special characters ',', ';',
       ':', or '='.

       Any amount of whitespace separates tokens in server entries, but is otherwise ignored. You
       may use backslash escape sequences (\n for LF, \t for HT, \b for BS, \r for CR,  \nnn  for
       decimal  (where  nnn  cannot  start with a 0), \0ooo for octal, and \xhh for hex) to embed
       non-printable characters or string delimiters in strings.  In quoted strings, a  backslash
       at the very end of a line will cause the backslash itself and the line feed (LF or NL, new
       line) character to be ignored, so that you can wrap long strings. Without the backslash at
       the line end, the line feed character would become part of the string.

       Warning:  while these resemble C-style escape sequences, they are not the same.  fetchmail
       only supports these eight styles.  C  supports  more  escape  sequences  that  consist  of
       backslash  (\)  and  a  single  character, but does not support decimal codes and does not
       require the leading 0 in octal notation.  Example: fetchmail interprets \233 the  same  as
       \xE9  (Latin small letter e with acute), where C would interpret \233 as octal 0233 = \x9B
       (CSI, control sequence introducer).

       Each server entry consists of one of the keywords 'poll' or 'skip', followed by  a  server
       name,  followed  by  server  options,  followed  by  any  number  of  user  (or  username)
       descriptions, followed by user options.  Note: the most common cause of syntax  errors  is
       mixing up user and server options or putting user options before the user descriptions.

       For backward compatibility, the word 'server' is a synonym for 'poll'.

       You can use the noise keywords 'and', 'with', 'has', 'wants', and 'options' anywhere in an
       entry to make it resemble English.  They are ignored, but can make entries much easier  to
       read at a glance.  The punctuation characters ':', ';' and ',' are also ignored.

   Poll versus Skip
       The  'poll' verb tells fetchmail to query this host when it is run with no arguments.  The
       'skip' verb tells fetchmail not to poll this host unless it is  explicitly  named  on  the
       command  line.   (The  'skip'  verb  allows you to experiment with test entries safely, or
       easily disable entries for hosts that are temporarily down.)


       Here are the legal options.  Keyword suffixes enclosed in square  brackets  are  optional.
       Those  corresponding to short command-line options are followed by '-' and the appropriate
       option letter.  If option is only relevant to a single mode of operation, it is  noted  as
       's' or 'm' for singledrop- or multidrop-mode, respectively.

       Here are the legal global options:

       Keyword             Opt   Mode   Function
       set daemon          -d           Set  a background poll interval in
       set postmaster                   Give the name of  the  last-resort
                                        mail   recipient   (default:  user
                                        running fetchmail, "postmaster" if
                                        run by the root user)
       set    bouncemail                Direct  error  mail  to the sender
       set no bouncemail                Direct error  mail  to  the  local
                                        postmaster     (as     per     the
                                        'postmaster' global option above).
       set no spambounce                Do not  bounce  spam-blocked  mail
       set    spambounce                Bounce  blocked  spam-blocked mail
                                        (as  per   the   'antispam'   user
                                        option) back to the destination as
                                        indicated  by   the   'bouncemail'
                                        global  option.   Warning:  Do not
                                        use this to bounce  spam  back  to
                                        the  sender  -  most  spam is sent
                                        with false sender address and thus
                                        this    option    hurts   innocent
       set no softbounce                Delete  permanently  undeliverable
                                        mail.  It  is  recommended  to use
                                        this option if  the  configuration
                                        has been thoroughly tested.
       set    softbounce                Keep   permanently   undeliverable
                                        mail as though a  temporary  error
                                        had occurred (default).
       set logfile         -L           Name of a file to append error and
                                        status    messages    to.     Only
                                        effective  in  daemon  mode and if
                                        fetchmail detaches.  If effective,
                                        overrides set syslog.
       set pidfile         -p           Name of the PID file.
       set idfile          -i           Name  of  the  file  to  store UID
                                        lists in.
       set    syslog                    Do    error    logging     through
                                        syslog(3).  May  be  overridden by
                                        set logfile.

       set no syslog                    Turn  off  error  logging  through
                                        syslog(3). (default)
       set properties                   String  value  that  is ignored by
                                        fetchmail   (may   be   used    by
                                        extension scripts).

       Here are the legal server options:

       Keyword          Opt   Mode   Function
       via                           Specify  DNS  name of mail server,
                                     overriding poll name
       proto[col]       -p           Specify       protocol       (case
                                     insensitive):  POP2,  POP3,  IMAP,
                                     APOP, KPOP
       local[domains]         m      Specify domain(s) to  be  regarded
                                     as local
       port                          Specify    TCP/IP   service   port
                                     (obsolete, use 'service' instead).
       service          -P           Specify service  name  (a  numeric
                                     value    is   also   allowed   and
                                     considered a TCP/IP port number).
       auth[enticate]                Set authentication  type  (default
       timeout          -t           Server   inactivity   timeout   in
                                     seconds (default 300)
       envelope         -E    m      Specify  envelope-address   header
       no envelope            m      Disable   looking   for   envelope
       qvirtual         -Q    m      Qmail  virtual  domain  prefix  to
                                     remove from user name
       aka                    m      Specify  alternate  DNS  names  of
                                     mail server
       interface        -I           specify IP interface(s) that  must
                                     be  up  for  server  poll  to take
       monitor          -M           Specify IP address to monitor  for
       plugin                        Specify  command  through which to
                                     make server connections.
       plugout                       Specify command through  which  to
                                     make listener connections.
       dns                    m      Enable  DNS  lookup  for multidrop
       no dns                 m      Disable DNS lookup for multidrop
       checkalias             m      Do comparison by  IP  address  for
       no checkalias          m      Do    comparison   by   name   for
                                     multidrop (default)
       uidl             -U           Force  POP3  to  use   client-side
                                     UIDLs (recommended)
       no uidl                       Turn  off  POP3 use of client-side
                                     UIDLs (default)
       interval                      Only check this site every N  poll
                                     cycles; N is a numeric argument.
       tracepolls                    Add  poll  tracing  information to
                                     the Received header
       principal                     Set   Kerberos   principal   (only
                                     useful with IMAP and kerberos)
       esmtpname                     Set      name      for     RFC2554
                                     authentication   to   the    ESMTP
       esmtppassword                 Set     password    for    RFC2554
                                     authentication   to   the    ESMTP
       bad-header                    How  to  treat messages with a bad
                                     header. Can be reject (default) or

       Here are the legal user descriptions and options:

       Keyword            Opt       Mode   Function
       user[name]         -u               This  is  the user description and
                                           must  come  first   after   server
                                           description   and  after  possible
                                           server options,  and  before  user

                                           It sets the remote user name if by
                                           itself or followed by 'there',  or
                                           the local user name if followed by
       is                                  Connect  local  and  remote   user
       to                                  Connect   local  and  remote  user
       pass[word]                          Specify remote account password
       ssl                                 Connect   to   server   over   the
                                           specified  base protocol using SSL
       sslcert                             Specify  file  for   client   side
                                           public SSL certificate
       sslcertck                           Enable strict certificate checking
                                           and abort connection  on  failure.
                                           Default   only   since   fetchmail
       no sslcertck                        Disable     strict     certificate
                                           checking and permit connections to
                                           continue on  failed  verification.
                                           Discouraged.  Should  only be used
                                           together with sslfingerprint.
       sslcertfile                         Specify  file  with   trusted   CA
       sslcertpath                         Specify c_rehash-ed directory with
                                           trusted CA certificates.
       sslfingerprint     <HASH>           Specify   the   expected    server
                                           certificate  finger  print from an
                                           MD5    hash.    Fetchmail     will
                                           disconnect  and log an error if it
                                           does not match.
       sslkey                              Specify  file  for   client   side
                                           private SSL key
       sslproto                            Force ssl protocol for connection
       folder             -r               Specify remote folder to query
       smtphost           -S               Specify smtp host(s) to forward to
       fetchdomains                 m      Specify  domains  for  which  mail
                                           should be fetched
       smtpaddress        -D               Specify the domain to  be  put  in
                                           RCPT TO lines
       smtpname                            Specify  the user and domain to be
                                           put in RCPT TO lines
       antispam           -Z               Specify  what  SMTP  returns   are
                                           interpreted as spam-policy blocks
       mda                -m               Specify MDA for local delivery
       bsmtp                               Specify BSMTP batch file to append
       preconnect                          Command to be executed before each
       postconnect                         Command  to be executed after each
       keep               -k               Do not delete seen  messages  from
                                           server    (for   POP3,   uidl   is
       flush              -F               Flush  all  seen  messages  before
                                           querying (DANGEROUS)
       limitflush                          Flush   all   oversized   messages
                                           before querying
       fetchall           -a               Fetch all messages whether seen or

       rewrite                             Rewrite  destination addresses for
                                           reply (default)
       stripcr                             Strip carriage returns  from  ends
                                           of lines
       forcecr                             Force  carriage returns at ends of
       pass8bits                           Force   BODY=8BITMIME   to   ESMTP
       dropstatus                          Strip  Status and X-Mozilla-Status
                                           lines out of incoming mail
       dropdelivered                       Strip Delivered-To  lines  out  of
                                           incoming mail
       mimedecode                          Convert  quoted-printable to 8-bit
                                           in MIME messages
       idle                                Idle  waiting  for  new   messages
                                           after each poll (IMAP only)
       no keep            -K               Delete  seen  messages from server
       no flush                            Do not  flush  all  seen  messages
                                           before querying (default)
       no fetchall                         Retrieve    only    new   messages
       no rewrite                          Do not rewrite headers
       no stripcr                          Do  not  strip  carriage   returns
       no forcecr                          Do  not  force carriage returns at
                                           EOL (default)
       no pass8bits                        Do  not  force  BODY=8BITMIME   to
                                           ESMTP listener (default)
       no dropstatus                       Do   not   drop   Status   headers
       no dropdelivered                    Do not drop  Delivered-To  headers
       no mimedecode                       Do not convert quoted-printable to
                                           8-bit in MIME messages (default)
       no idle                             Do  not  idle  waiting   for   new
                                           messages  after  each  poll  (IMAP
       limit              -l               Set message size limit
       warnings           -w               Set message size warning interval
       batchlimit         -b               Max  #  messages  to  forward   in
                                           single connect
       fetchlimit         -B               Max  # messages to fetch in single
       fetchsizelimit                      Max # message sizes  to  fetch  in
                                           single transaction
       fastuidl                            Use binary search for first unseen
                                           message (POP3 only)
       expunge            -e               Perform an expunge  on  every  #th
                                           message (IMAP and POP3 only)
       properties                          String   value   is   ignored   by
                                           fetchmail   (may   be   used    by
                                           extension scripts)

       All  user  options must begin with a user description (user or username option) and follow
       all server descriptions and options.

       In the .fetchmailrc file, the 'envelope' string argument may be preceded by a  whitespace-
       separated  number.   This number, if specified, is the number of such headers to skip over
       (that is, an argument of 1 selects  the  second  header  of  the  given  type).   This  is
       sometimes  useful  for  ignoring bogus envelope headers created by an ISP's local delivery
       agent or internal forwards (through mail inspection systems, for instance).

   Keywords Not Corresponding To Option Switches
       The 'folder' and 'smtphost' options (unlike their command-line  equivalents)  can  take  a
       space- or comma-separated list of names following them.

       All options correspond to the obvious command-line arguments, except the following: 'via',
       'interval', 'aka', 'is', 'to', 'dns'/'no dns', 'checkalias'/'no  checkalias',  'password',
       'preconnect',   'postconnect',   'localdomains',   'stripcr'/'no  stripcr',  'forcecr'/'no
       forcecr',  'pass8bits'/'no  pass8bits'   'dropstatus/no   dropstatus',   'dropdelivered/no
       dropdelivered', 'mimedecode/no mimedecode', 'no idle', and 'no envelope'.

       The  'via'  option  is for if you want to have more than one configuration pointing at the
       same site.  If it is present, the string argument will be taken as the actual DNS name  of
       the  mail  server  host to query.  This will override the argument of poll, which can then
       simply be a distinct label for the configuration (e.g., what you would give on the command
       line to explicitly query this host).

       The  'interval'  option  (which takes a numeric argument) allows you to poll a server less
       frequently than the basic poll interval.  If you say 'interval N' the server  this  option
       is attached to will only be queried every N poll intervals.

   Singledrop versus Multidrop options
       Please  ensure you read the section titled THE USE AND ABUSE OF MULTIDROP MAILBOXES if you
       intend to use multidrop mode.

       The 'is' or 'to' keywords associate the following local (client) name(s)  (or  server-name
       to  client-name  mappings separated by =) with the mail server user name in the entry.  If
       an is/to list has '*' as its last name, unrecognized names are simply passed through. Note
       that until fetchmail version 6.3.4 inclusively, these lists could only contain local parts
       of user names (fetchmail would only look  at  the  part  before  the  @  sign).  fetchmail
       versions  6.3.5  and newer support full addresses on the left hand side of these mappings,
       and they take precedence over any 'localdomains', 'aka', 'via' or similar mappings.

       A single local name can be used to support redirecting your mail when your username on the
       client  machine  is  different  from  your  name on the mail server.  When there is only a
       single local name, mail is forwarded to that local username regardless  of  the  message's
       Received, To, Cc, and Bcc headers.  In this case, fetchmail never does DNS lookups.

       When  there is more than one local name (or name mapping), fetchmail looks at the envelope
       header, if configured, and otherwise at the Received, To, Cc, and Bcc headers of retrieved
       mail  (this  is 'multidrop mode').  It looks for addresses with host name parts that match
       your poll name or your 'via', 'aka' or 'localdomains' options, and usually also  for  host
       name  parts  which  DNS  tells  it  are aliases of the mail server.  See the discussion of
       'dns', 'checkalias', 'localdomains', and 'aka' for details on how matching  addresses  are

       If  fetchmail  cannot  match  any mail server usernames or localdomain addresses, the mail
       will be bounced.  Normally it will be bounced to  the  sender,  but  if  the  'bouncemail'
       global  option  is  off,  the  mail  will  go  to  the local postmaster instead.  (see the
       'postmaster' global option). See also BUGS.

       The 'dns' option (normally on) controls the way addresses  from  multidrop  mailboxes  are
       checked.   On, it enables logic to check each host address that does not match an 'aka' or
       'localdomains' declaration by looking it up with DNS.  When  a  mail  server  username  is
       recognized  attached  to a matching host name part, its local mapping is added to the list
       of local recipients.

       The 'checkalias' option (normally off) extends the lookups performed by the 'dns'  keyword
       in multidrop mode, providing a way to cope with remote MTAs that identify themselves using
       their canonical name, while they are polled using an alias.  When such a server is polled,
       checks  to  extract the envelope address fail, and fetchmail reverts to delivery using the
       To/Cc/Bcc headers (See below 'Header versus Envelope addresses').  Specifying this  option
       instructs  fetchmail  to  retrieve all the IP addresses associated with both the poll name
       and the name used by the remote MTA and to do a comparison  of  the  IP  addresses.   This
       comes  in  handy  in  situations where the remote server undergoes frequent canonical name
       changes, that would otherwise require modifications to the rcfile.   'checkalias'  has  no
       effect if 'no dns' is specified in the rcfile.

       The 'aka' option is for use with multidrop mailboxes.  It allows you to pre-declare a list
       of DNS aliases for a server.  This is an optimization hack that allows you to trade  space
       for  speed.  When fetchmail, while processing a multidrop mailbox, grovels through message
       headers looking for names of the mail server, pre-declaring common ones can save  it  from
       having  to  do DNS lookups.  Note: the names you give as arguments to 'aka' are matched as
       suffixes -- if you specify (say) 'aka', this will match not just  a  host  name,  but any host name that ends with ''; such as (say)

       The 'localdomains' option allows you to declare a list of domains which  fetchmail  should
       consider  local.   When  fetchmail  is  parsing  address  lines  in multidrop modes, and a
       trailing segment of a host name matches a declared local domain, that  address  is  passed
       through to the listener or MDA unaltered (local-name mappings are not applied).

       If  you  are  using  'localdomains',  you  may  also  need to specify 'no envelope', which
       disables fetchmail's normal attempt to deduce an envelope address from the  Received  line
       or  X-Envelope-To header or whatever header has been previously set by 'envelope'.  If you
       set 'no envelope' in the defaults entry it is possible to undo that in individual  entries
       by  using  'envelope  <string>'.   As  a  special case, 'envelope "Received"' restores the
       default parsing of Received lines.

       The password option requires a string argument, which is the password to be used with  the
       entry's server.

       The  'preconnect' keyword allows you to specify a shell command to be executed just before
       each time fetchmail establishes a mail server connection.  This may be useful if  you  are
       attempting  to  set  up  secure  POP  connections  with the aid of ssh(1).  If the command
       returns a nonzero status, the poll of that mail server will be aborted.

       Similarly, the 'postconnect' keyword similarly allows you to specify a shell command to be
       executed just after each time a mail server connection is taken down.

       The  'forcecr'  option  controls  whether  lines  terminated  by  LF  only  are given CRLF
       termination before forwarding.  Strictly speaking  RFC821  requires  this,  but  few  MTAs
       enforce  the  requirement  so this option is normally off (only one such MTA, qmail, is in
       significant use at time of writing).

       The 'stripcr' option controls whether carriage returns are stripped out of retrieved  mail
       before  it is forwarded.  It is normally not necessary to set this, because it defaults to
       'on' (CR stripping enabled) when  there  is  an  MDA  declared  but  'off'  (CR  stripping
       disabled)  when forwarding is via SMTP.  If 'stripcr' and 'forcecr' are both on, 'stripcr'
       will override.

       The 'pass8bits' option exists to cope with Microsoft mail programs that  stupidly  slap  a
       "Content-Transfer-Encoding:  7bit"  on everything.  With this option off (the default) and
       such a header present, fetchmail declares BODY=7BIT to  an  ESMTP-capable  listener;  this
       causes  problems for messages actually using 8-bit ISO or KOI-8 character sets, which will
       be garbled by having the high bits of all characters  stripped.   If  'pass8bits'  is  on,
       fetchmail  is  forced  to  declare  BODY=8BITMIME  to  any ESMTP-capable listener.  If the
       listener is 8-bit-clean (as all the major ones now are)  the  right  thing  will  probably

       The  'dropstatus'  option  controls whether nonempty Status and X-Mozilla-Status lines are
       retained in fetched mail (the default) or discarded.  Retaining them allows  your  MUA  to
       see  what  messages  (if  any)  were marked seen on the server.  On the other hand, it can
       confuse some new-mail notifiers, which assume that anything with a Status line in  it  has
       been  seen.   (Note:  the  empty  Status  lines  inserted  by  some  buggy POP servers are
       unconditionally discarded.)

       The 'dropdelivered' option controls whether Delivered-To headers will be kept  in  fetched
       mail (the default) or discarded. These headers are added by qmail and Postfix mail servers
       in order to avoid mail loops but may get in your way if you try to "mirror" a mail  server
       within the same domain. Use with caution.

       The 'mimedecode' option controls whether MIME messages using the quoted-printable encoding
       are automatically converted into pure 8-bit data. If you are delivering mail to an  ESMTP-
       capable,  8-bit-clean  listener  (that includes all of the major MTAs like sendmail), then
       this will automatically convert quoted-printable message headers and data into 8-bit data,
       making it easier to understand when reading mail. If your e-mail programs know how to deal
       with MIME messages, then this option is not needed.   The  mimedecode  option  is  off  by
       default, because doing RFC2047 conversion on headers throws away character-set information
       and can lead to bad results if the encoding of the headers differs from the body encoding.

       The 'idle' option is intended to be used with IMAP servers  supporting  the  RFC2177  IDLE
       command  extension,  but  does  not  strictly require it.  If it is enabled, and fetchmail
       detects that IDLE is supported, an IDLE will be issued at the end of each poll.  This will
       tell  the  IMAP  server to hold the connection open and notify the client when new mail is
       available.  If IDLE is not supported, fetchmail will simulate it by  periodically  issuing
       NOOP. If you need to poll a link frequently, IDLE can save bandwidth by eliminating TCP/IP
       connects and LOGIN/LOGOUT sequences. On the other hand, an IDLE connection will eat almost
       all  of  your  fetchmail's time, because it will never drop the connection and allow other
       polls to occur unless the server times out the IDLE.  It also does not work with  multiple
       folders; only the first folder will ever be polled.

       The  'properties'  option is an extension mechanism.  It takes a string argument, which is
       ignored by fetchmail itself.  The string argument  may  be  used  to  store  configuration
       information  for  scripts  which  require it.  In particular, the output of '--configdump'
       option will make properties associated with a user entry readily  available  to  a  Python

   Miscellaneous Run Control Options
       The  words  'here' and 'there' have useful English-like significance.  Normally 'user eric
       is esr' would mean that mail for the remote user 'eric' is to be delivered to  'esr',  but
       you can make this clearer by saying 'user eric there is esr here', or reverse it by saying
       'user esr here is eric there'

       Legal protocol identifiers for use with the 'protocol' keyword are:

           auto (or AUTO) (legacy, to be removed from future release)
           pop2 (or POP2) (legacy, to be removed from future release)
           pop3 (or POP3)
           sdps (or SDPS)
           imap (or IMAP)
           apop (or APOP)
           kpop (or KPOP)

       Legal authentication types are 'any', 'password', 'kerberos', 'kerberos_v4', 'kerberos_v5'
       and  'gssapi',  'cram-md5',  'otp', 'msn' (only for POP3), 'ntlm', 'ssh', 'external' (only
       IMAP).  The 'password' type specifies authentication by normal transmission of a  password
       (the  password  may  be  plain text or subject to protocol-specific encryption as in CRAM-
       MD5); 'kerberos' tells fetchmail to try to get a Kerberos ticket  at  the  start  of  each
       query  instead, and send an arbitrary string as the password; and 'gssapi' tells fetchmail
       to use GSSAPI authentication.  See the description of the 'auth' keyword for more.

       Specifying 'kpop' sets POP3 protocol over  port  1109  with  Kerberos  V4  authentication.
       These defaults may be overridden by later options.

       There  are some global option statements: 'set logfile' followed by a string sets the same
       global specified by --logfile.  A command-line --logfile option will override  this.  Note
       that  --logfile  is  only effective if fetchmail detaches itself from the terminal and the
       logfile already exists before fetchmail is run, and it overrides --syslog  in  this  case.
       Also,  'set  daemon' sets the poll interval as --daemon does.  This can be overridden by a
       command-line --daemon option; in particular --daemon 0 can be  used  to  force  foreground
       operation.  The  'set  postmaster'  statement  sets  the  address  to which multidrop mail
       defaults if there are no local matches.  Finally,  'set  syslog'  sends  log  messages  to


   Fetchmail crashing
       There  are  various  ways in that fetchmail may "crash", i. e. stop operation suddenly and
       unexpectedly. A "crash" usually refers to an error condition that  the  software  did  not
       handle  by itself. A well-known failure mode is the "segmentation fault" or "signal 11" or
       "SIGSEGV" or just "segfault" for short. These can be caused by  hardware  or  by  software
       problems.  Software-induced  segfaults  can  usually  be reproduced easily and in the same
       place, whereas hardware-induced segfaults can go away if  the  computer  is  rebooted,  or
       powered  off  for  a  few  hours,  and  can happen in random locations even if you use the
       software the same way.

       For solving hardware-induced segfaults, find the faulty component and  repair  or  replace
       it.  The Sig11 FAQ ⟨⟩ may help you with details.

       For solving software-induced segfaults, the developers may need a "stack backtrace".

   Enabling fetchmail core dumps
       By  default,  fetchmail  suppresses  core dumps as these might contain passwords and other
       sensitive information. For debugging fetchmail crashes, obtaining a "stack backtrace" from
       a  core dump is often the quickest way to solve the problem, and when posting your problem
       on a mailing list, the developers may ask you for a "backtrace".

       1. To get useful backtraces, fetchmail needs to be installed without getting  stripped  of
       its  compilation  symbols.   Unfortunately,  most  binary  packages that are installed are
       stripped, and core files from symbol-stripped programs are worthless. So you may  need  to
       recompile fetchmail. On many systems, you can type

               file `which fetchmail`

       to  find  out  if  fetchmail  was  symbol-stripped  or not. If yours was unstripped, fine,
       proceed, if it was stripped, you need to recompile the  source  code  first.  You  do  not
       usually need to install fetchmail in order to debug it.

       2.  The shell environment that starts fetchmail needs to enable core dumps. The key is the
       "maximum core (file) size" that can usually be configured with a  tool  named  "limit"  or
       "ulimit".  See  the  documentation  for your shell for details. In the popular bash shell,
       "ulimit -Sc unlimited" will allow the core dump.

       3. You need to tell fetchmail, too, to allow core dumps. To do this,  run  fetchmail  with
       the -d0 -v options.  It is often easier to also add --nosyslog -N as well.

       Finally,  you need to reproduce the crash. You can just start fetchmail from the directory
       where you compiled it by typing ./fetchmail, so the complete command line will start  with
       ./fetchmail -Nvd0 --nosyslog and perhaps list your other options.

       After  the  crash,  run your debugger to obtain the core dump.  The debugger will often be
       GNU GDB, you can then type (adjust paths as necessary) gdb ./fetchmail fetchmail.core  and
       then,  after  GDB  has  started  up  and read all its files, type backtrace full, save the
       output (copy & paste will do, the backtrace will be read by a human) and then type quit to
       leave gdb.  Note: on some systems, the core files have different names, they might contain
       a number instead of the program name, or number and name, but it will usually have  "core"
       as part of their name.


       When  trying  to  determine  the originating address of a message, fetchmail looks through
       headers in the following order:

               Resent-Sender: (ignored if it does not contain an @ or !)
               Sender: (ignored if it does not contain an @ or !)

       The originating address is used for logging,  and  to  set  the  MAIL  FROM  address  when
       forwarding to SMTP.  This order is intended to cope gracefully with receiving mailing list
       messages in multidrop mode. The intent is that if a local  address  does  not  exist,  the
       bounce  message  will  not  be  returned  blindly to the author or to the list itself, but
       rather to the list manager (which is less annoying).

       In multidrop mode, destination headers are processed as follows:  First,  fetchmail  looks
       for  the  header  specified  by  the  'envelope'  option  in  order to determine the local
       recipient address. If the mail is addressed to more than one recipient, the Received  line
       will not contain any information regarding recipient addresses.

       Then  fetchmail  looks  for  the  Resent-To:,  Resent-Cc:, and Resent-Bcc: lines.  If they
       exist,  they  should  contain  the  final  recipients  and  have  precedence  over   their
       To:/Cc:/Bcc:  counterparts.   If  the  Resent-* lines do not exist, the To:, Cc:, Bcc: and
       Apparently-To: lines are looked for. (The presence of a Resent-To: is taken to imply  that
       the  person  referred  by  the  To:  address has already received the original copy of the


       Note that although there are password declarations in a good many of the  examples  below,
       this is mainly for illustrative purposes.  We recommend stashing account/password pairs in
       your $HOME/.netrc file, where they can be used not just by fetchmail  but  by  ftp(1)  and
       other programs.

       The basic format is:

              poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD


              poll protocol pop3 username "jsmith" password "secret1"

       Or, using some abbreviations:

              poll proto pop3 user "jsmith" password "secret1"

       Multiple servers may be listed:

              poll proto pop3 user "jsmith" pass "secret1"
              poll proto pop2 user "John.Smith" pass "My^Hat"

       Here is the same version with more whitespace and some noise words:

              poll proto pop3
                   user "jsmith", with password secret1, is "jsmith" here;
              poll proto pop2:
                   user "John.Smith", with password "My^Hat", is "John.Smith" here;

       If you need to include whitespace in a parameter string or start the latter with a number,
       enclose the string in double quotes.  Thus:

              poll with proto pop3:
                   user "jsmith" there has password "4u but u cannot krak this"
                   is jws here and wants mda "/bin/mail"

       You may have an initial server description headed by the  keyword  'defaults'  instead  of
       'poll'  followed  by  a name.  Such a record is interpreted as defaults for all queries to
       use. It may be overwritten by individual server descriptions.  So, you could write:

              defaults proto pop3
                   user "jsmith"
                   pass "secret1"
                   user "jjsmith" there has password "secret2"

       It is possible to specify more than one user per server.  The 'user' keyword leads  off  a
       user  description,  and  every  user  specification in a multi-user entry must include it.
       Here is an example:

              poll proto pop3 port 3111
                   user "jsmith" with pass "secret1" is "smith" here
                   user jones with pass "secret2" is "jjones" here keep

       This associates the local username 'smith' with the username 'jsmith' and
       the  local username 'jjones' with the username 'jones'.  Mail for 'jones'
       is kept on the server after download.

       Here is what a simple retrieval configuration for a multidrop mailbox looks like:

                   user maildrop with pass secret1 to golux 'hurkle'='happy' snark here

       This says that the mailbox of account 'maildrop' on the server is  a  multidrop  box,  and
       that  messages  in  it  should  be parsed for the server user names 'golux', 'hurkle', and
       'snark'.  It further specifies that 'golux' and 'snark' have the same name on  the  client
       as  on  the  server,  but mail for server user 'hurkle' should be delivered to client user

       Note that fetchmail, until version 6.3.4, did NOT allow  full  user@domain  specifications
       here,   these   would   never  match.   Fetchmail  6.3.5  and  newer  support  user@domain
       specifications on the left-hand side of a user mapping.

       Here is an example of another kind of multidrop connection:

              poll localdomains
                   envelope X-Envelope-To
                   user maildrop with pass secret1 to * here

       This also says that the mailbox of account 'maildrop' on the server is  a  multidrop  box.
       It  tells fetchmail that any address in the or domains (including
       sub-domain addresses like '') should  be  passed  through  to  the
       local SMTP listener without modification.  Be careful of mail loops if you do this!

       Here  is  an  example configuration using ssh and the plugin option.  The queries are made
       directly on the stdin and stdout of  imapd  via  ssh.   Note  that  in  this  setup,  IMAP
       authentication can be skipped.

              poll with proto imap:
                   plugin "ssh %h /usr/sbin/imapd" auth ssh;
                   user esr is esr here


       Use  the  multiple-local-recipients  feature  with  caution -- it can bite.  All multidrop
       features are ineffective in ETRN and ODMR modes.

       Also, note that in multidrop mode duplicate mails may be suppressed.  A piece of  mail  is
       considered duplicate if it does not have a discernible envelope recipient address, has the
       same header as the message immediately preceding and more than one addressee.   Such  runs
       of  messages  may  be  generated  when copies of a message addressed to multiple users are
       delivered to a multidrop box. (To be precise, fetchmail 6.2.5 through  6.4.X  use  an  MD5
       hash  of  the  raw  message  header,  and  only  fetchmail 6.4.16+ document this properly.
       Fetchmail 5.0.8 (1999-09-14) through 6.2.4 used only the  Message-ID  header.   5.0.7  and
       older did not suppress duplicates.)

       Note  that this duplication killer code checking the entire header is very restrictive and
       may not suppress many duplicates in practice - for  instance,  if  some  X-Original-To  or
       Delivered-To header differs.  This is intentional and correct in such situations: wherever
       envelope information is available, it should be used for reliable delivery of mailing list
       and  blind  carbon copy (Bcc) messages. See the subsection Duplicate suppression below for

   Header versus Envelope addresses
       The fundamental problem is that by having your mail server toss several peoples' mail in a
       single maildrop box, you may have thrown away potentially vital information about who each
       piece of mail was actually addressed to (the 'envelope address', as opposed to the  header
       addresses  in  the  RFC822 To/Cc headers - the Bcc is not available at the receiving end).
       This 'envelope address' is the address you need in order to reroute mail properly.

       Sometimes fetchmail can deduce the envelope address.  If the mail server MTA  is  sendmail
       and  the  item of mail had just one recipient, the MTA will have written a 'by/for' clause
       that gives the envelope addressee into  its  Received  header.  But  this  does  not  work
       reliably  for  other MTAs, nor if there is more than one recipient.  By default, fetchmail
       looks for envelope addresses in  these  lines;  you  can  restore  this  default  with  -E
       "Received" or 'envelope Received'.

       As  a  better alternative, some SMTP listeners and/or mail servers insert a header in each
       message containing a copy of the envelope addresses.  This  header  (when  it  exists)  is
       often  'X-Original-To',  'Delivered-To'  or 'X-Envelope-To'.  Fetchmail's assumption about
       this can be changed with the -E or 'envelope'  option.   Note  that  writing  an  envelope
       header  of  this kind exposes the names of recipients (including blind-copy recipients) to
       all receivers of the messages, so the upstream must store one  copy  of  the  message  per
       recipient to avoid becoming a privacy problem.

       Postfix,  since  version 2.0, writes an X-Original-To: header which contains a copy of the
       envelope as it was received.

       Qmail and Postfix generally write a 'Delivered-To' header upon delivering the  message  to
       the  mail spool and use it to avoid mail loops.  Qmail virtual domains however will prefix
       the user name with a string that normally matches the user's domain. To remove this prefix
       you can use the -Q or 'qvirtual' option.

       Sometimes,  unfortunately,  neither  of  these  methods works.  That is the point when you
       should contact your ISP and ask them to provide such an envelope header,  and  you  should
       not  use multidrop in this situation.  When they all fail, fetchmail must fall back on the
       contents of To/Cc headers (Bcc headers are not available - see below) to try to  determine
       recipient  addressees  --  and these are unreliable.  In particular, mailing-list software
       often ships mail with only the list broadcast address in the To: header.

       Note that a future version of fetchmail may remove To/Cc parsing!

       When fetchmail cannot deduce a recipient address that is local, and the intended recipient
       address was anyone other than fetchmail's invoking user, mail will get lost.  This is what
       makes the multidrop feature risky without proper envelope information.

       A related problem is that when you blind-copy a  mail  message,  the  Bcc  information  is
       carried  only  as  envelope  address  (it  is removed from the headers by the sending mail
       server, so fetchmail can see it only if there is an X-Envelope-To header).   Thus,  blind-
       copying to someone who gets mail over a fetchmail multidrop link will fail unless the mail
       server host routinely writes X-Envelope-To or an equivalent header into messages  in  your

       In  conclusion,  mailing lists and Bcc'd mail can only work if the server you are fetching

       (1)    stores one copy of the message per recipient in your domain and

       (2)    records the envelope information in a special header (X-Original-To,  Delivered-To,

   Good Ways To Use Multidrop Mailboxes
       Multiple  local  names  can be used to administer a mailing list from the client side of a
       fetchmail collection.  Suppose your name is 'esr', and you want to both pick up  your  own
       mail  and  maintain  a mailing list called (say) "fetchmail-friends", and you want to keep
       the alias list on your client machine.

       On your server, you can alias 'fetchmail-friends' to 'esr'; then,  in  your  .fetchmailrc,
       declare 'to esr fetchmail-friends here'.  Then, when mail including 'fetchmail-friends' as
       a local address gets fetched, the list name will be appended to  the  list  of  recipients
       your  SMTP  listener sees.  Therefore it will undergo alias expansion locally.  Be sure to
       include 'esr' in the local alias expansion of fetchmail-friends, or  you  will  never  see
       mail  sent  only to the list.  Also be sure that your listener has the "me-too" option set
       (sendmail's -oXm command-line option or OXm declaration) so your name is not removed  from
       alias expansions in messages you send.

       This  trick  is  not  without  its  problems,  however.  You will begin to see this when a
       message comes in that is addressed only to a mailing list you do not have  declared  as  a
       local  name.   Each  such  message  will  feature an 'X-Fetchmail-Warning' header which is
       generated because fetchmail cannot find a valid local name  in  the  recipient  addresses.
       Such  messages  default  (as  was described above) to being sent to the local user running
       fetchmail, but the program has no way to know that this is actually the right thing.

   Bad Ways To Abuse Multidrop Mailboxes
       Multidrop mailboxes and fetchmail serving multiple users in daemon mode do not  mix.   The
       problem,  again,  is  mail from mailing lists, which typically does not have an individual
       recipient address on it.   Unless fetchmail can deduce an envelope address, such mail will
       only  go  to  the account running fetchmail (probably root).  Also, blind-copied users are
       very likely never to see their mail at all.

       If you are tempted to use fetchmail to retrieve mail for multiple users from a single mail
       drop via POP or IMAP, think again (and reread the section on header and envelope addresses
       above).  It would be smarter to just let the mail sit in the mail server's queue  and  use
       fetchmail's  ETRN  or ODMR modes to trigger SMTP sends periodically (of course, this means
       you have to poll more frequently than the mail server's expiry  period).   If  you  cannot
       arrange this, try setting up a UUCP feed.

       If  you  absolutely must use multidrop for this purpose, make sure your mail server writes
       an envelope-address header that fetchmail can see.  Otherwise you will lose  mail  and  it
       will come back to haunt you.

   Speeding Up Multidrop Checking
       Normally,  when  multiple  users  are  declared  fetchmail extracts recipient addresses as
       described above and checks each host part with DNS to see if it is an alias  of  the  mail
       server.   If so, the name mappings described in the "to ... here" declaration are done and
       the mail locally delivered.

       This is a convenient but also slow method.   To  speed  it  up,  pre-declare  mail  server
       aliases  with  'aka';  these  are checked before DNS lookups are done.  If you are certain
       your aka list contains all DNS aliases of the mail server (and all MX names pointing at it
       -  note  this  may  change  in  a future version) you can declare 'no dns' to suppress DNS
       lookups entirely and only match against the aka list.

   Duplicate suppression on multidrop
       If fetchmail's duplicate suppression code  does  not  kick  in  for  your  multidrop  mail
       account,  other options is using sieve, or for instance Courier's maildrop package (and in
       particular, its reformail program with the -D option) as the delivery agent  (either  from
       fetchmail, or from your local mail server that fetchmail injects into).


       Support  for  socks4/5 is a compile time configuration option. Once compiled in, fetchmail
       will always use the socks libraries and configuration on your system, there  are  no  run-
       time  switches  in  fetchmail  -  but you can still configure SOCKS: you can specify which
       SOCKS configuration file is used in the SOCKS_CONF environment variable.

       For instance, if you wanted to bypass  the  SOCKS  proxy  altogether  and  have  fetchmail
       connect directly, you could just pass SOCKS_CONF=/dev/null in the environment, for example
       (add your usual command line options - if any - to the end of this line):

       env SOCKS_CONF=/dev/null fetchmail


       To facilitate the use of fetchmail in shell scripts, an exit status code  is  returned  to
       give an indication of what occurred during a given connection.

       The exit codes returned by fetchmail are as follows:

       0      One  or  more  messages  were  successfully  retrieved  (or,  if  the -c option was
              selected, were found waiting but not retrieved).

       1      There was no mail awaiting retrieval.  (There may have been old mail still  on  the
              server but not selected for retrieval.) If you do not want "no mail" to be an error
              condition (for instance, for cron jobs), use a POSIX-compliant shell and add

              || [ $? -eq 1 ]

              to the end of the fetchmail command line, note that this leaves 0 untouched, maps 1
              to 0, and maps all other codes to 1. See also item #C8 in the FAQ.

       2      An error was encountered when attempting to open a socket to retrieve mail.  If you
              do not know what a socket is, do not worry about  it  --  just  treat  this  as  an
              'unrecoverable  error'.   This error can also be because a protocol fetchmail wants
              to use is not listed in /etc/services.

       3      The user authentication step failed.   This  usually  means  that  a  bad  user-id,
              password, or APOP id was specified.  Or it may mean that you tried to run fetchmail
              under circumstances where it did not have standard input attached to a terminal and
              could not prompt for a missing password.

       4      Some sort of fatal protocol error was detected.

       5      There  was  a syntax error in the arguments to fetchmail, or a pre- or post-connect
              command failed.

       6      The run control file had bad permissions.

       7      There was an error condition reported by the server.  Can also  fire  if  fetchmail
              timed out while waiting for the server.

       8      Client-side  exclusion  error.   This  means fetchmail either found another copy of
              itself already running, or failed in such a way that it is not sure whether another
              copy is running.

       9      The  user authentication step failed because the server responded "lock busy".  Try
              again after a brief pause!  This error is not implemented for  all  protocols,  nor
              for all servers.  If not implemented for your server, "3" will be returned instead,
              see above.  May be returned when talking to  qpopper  or  other  servers  that  can
              respond with "lock busy" or some similar text containing the word "lock".

       10     The fetchmail run failed while trying to do an SMTP port open or transaction.

       11     Fatal  DNS  error.  Fetchmail encountered an error while performing a DNS lookup at
              startup and could not proceed.

       12     BSMTP batch file could not be opened.

       13     Poll terminated by a fetch limit (see the --fetchlimit option).

       14     Server busy indication.

       23     Internal error.  You should see a message on standard error with details.

       24 - 26, 28, 29
              These are internal codes and should not appear externally.

       When fetchmail queries more than one host, return status is 0 if  any  query  successfully
       retrieved mail. Otherwise the returned error status is that of the last host queried.


       ~/.fetchmailrc, $HOME/.fetchmailrc, $HOME_ETC/.fetchmailrc, $FETCHMAILHOME/fetchmailrc
            default run control file (location can be overridden with environment variables)

       ~/.fetchids, $HOME/.fetchids, $HOME_ETC/.fetchids, $FETCHMAILHOME/.fetchids
            default location of file recording last message UIDs seen per host.  (location can be
            overridden with environment variables)

       ~/,             $HOME/,              $HOME_ETC/,
            default  location  of  lock  file  (sometimes  called pidfile or PID file, see option
            pidfile)  to  help  prevent  concurrent  runs  (non-root  mode).   (location  can  be
            overridden with environment variables)

       ~/.netrc, $HOME/.netrc, $HOME_ETC/.netrc
            your  FTP  run  control  file, which (if present) will be searched for passwords as a
            last resort before prompting for one interactively.  (location can be overridden with
            environment variables)

            lock file (pidfile) to help prevent concurrent runs (root mode, Linux systems).

            lock  file  (pidfile)  to  help  prevent  concurrent runs (root mode, systems without


       Fetchmail's behavior can be altered by providing it with environment variables.  Some  may
       alter  the  operation  of  libraries  that fetchmail links against, for instance, OpenSSL.
       Note that in daemon mode, you will need to quit the background daemon process and start  a
       new fetchmail daemon for environment changes to take effect.

              If  this  environment  variable  is  set  to  a  valid and existing directory name,
              fetchmail will read $FETCHMAILHOME/fetchmailrc (the dot is missing in  this  case),
              $FETCHMAILHOME/.fetchids   (keeping   its   dot)  and  $FETCHMAILHOME/
              (without dot) rather than from the user's  home  directory.   The  .netrc  file  is
              always  looked  for in the invoking user's home directory (or $HOME_ETC) regardless
              of FETCHMAILHOME's setting.

              If this environment variable is set, it is used as the name  of  the  calling  user
              (default  local name) for purposes such as mailing error notifications.  Otherwise,
              if either the LOGNAME or USER variable is correctly set  (e.g.,  the  corresponding
              UID  matches the session user ID) then that name is used as the default local name.
              Otherwise getpwuid(3) must be able to retrieve a password entry for the session  ID
              (this  elaborate logic is designed to handle the case of multiple names per user ID

              (since v6.3.22): If this environment variable is set and not empty, fetchmail  will
              disable   a   countermeasure   against   an   SSL   CBC   IV   attack  (by  setting
              SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS).  This is a security risk, but may be necessary
              for  connecting  to certain non-standards-conforming servers.  See fetchmail's NEWS
              file and fetchmail-SA-2012-01.txt for details.  Earlier fetchmail versions (v6.3.21
              and  older) used to disable this countermeasure, but v6.3.22 no longer does that as
              a safety precaution.

              (since v6.3.9): If this environment variable is defined at  all  (even  if  empty),
              fetchmail  will forgo the POP3 TOP command and always use RETR. This can be used as
              a workaround when TOP does not work properly.

              (since v6.3.17): If this environment variable is set and not empty, fetchmail  will
              always  load  the  default  X.509  trusted  certificate  locations  for  SSL/TLS CA
              certificates, even if  --sslcertfile  and  --sslcertpath  are  given.   The  latter
              locations  take  precedence  over  the system default locations.  This is useful in
              case there are broken certificates in the system directories and the  user  has  no
              administrator privileges to remedy the problem.

              (since  v6.4.25):  If fetchmail is compiled and linked with wolfSSL, if wolfSSL was
              built with --enable-debug, and if this environment variable is set and  not  empty,
              then  enable  wolfSSL's  debug mode. This will emit huge amounts of debug output to

       HOME   (documented since 6.4.1):  This  variable  is  normally  set  to  the  user's  home
              directory.  If  it  is  set  to  a different directory than what is in the password
              database, HOME takes precedence.

              (documentation corrected to match behaviour of code since 6.4.1): If  the  HOME_ETC
              variable  is  set, it will override fetchmail's idea of $HOME, i. e. fetchmail will
              read .fetchmailrc, .fetchids, and .netrc from $HOME_ETC  instead  of
              $HOME (or if HOME is also unset, from the passwd file's home directory location).

              If  HOME_ETC  and  FETCHMAILHOME  are  both set, FETCHMAILHOME takes precedence and
              HOME_ETC will be ignored.

              (only if SOCKS support is compiled in) this variable is used by the  socks  library
              to  find  out  which  configuration  file  it should read. Set this to /dev/null to
              bypass the SOCKS proxy.

              (with truly OpenSSL 1.1.1 compatible library):  overrides  OpenSSL's  idea  of  the
              default  trust  directory  or path (which contains individual certificate files and
              hashed symlinks),  see  the  SSL_CTX_set_default_verify_paths(3)  manual  page  for
              details,  it may be in the openssl development package.  If using another library's
              OpenSSL compatibility interface, this may  not  work.   Since  this  variable  only
              specifies a default value, the option --sslcertpath takes precedence if given.

              (with  truly  OpenSSL  1.1.1  compatible  library): overrides OpenSSL's idea of the
              default  trust  certificate  bundle  file  (which  contains  a   concatenation   of
              base64-encoded       certificates       in      PEM      format),      see      the
              SSL_CTX_set_default_verify_paths(3) manual page for  details,  it  may  be  in  the
              openssl  development  package.   If  using  another library's OpenSSL compatibility
              interface, this may not work.  Since this variable only specifies a default  value,
              the option --sslcertfile takes precedence if given.


       If  a  fetchmail  daemon  is running as root, SIGUSR1 wakes it up from its sleep phase and
       forces a poll of all non-skipped servers. For compatibility reasons, SIGHUP  can  also  be
       used in 6.3.X but may not be available in future fetchmail versions.

       If  fetchmail  is  running  in daemon mode as non-root, use SIGUSR1 to wake it (this is so
       SIGHUP due to logout can retain the default action of killing it).

       Running fetchmail in foreground while a background fetchmail is running will do  whichever
       of these is appropriate to wake it up.


       Please  check  the  NEWS  file  that shipped with fetchmail for more known bugs than those
       listed here.

       Fetchmail cannot handle user names that contain blanks after a "@" character, for instance
       "demonstr@ti  on".  These  are  rather  uncommon and only hurt when using UID-based --keep
       setups, so the 6.X.Y versions of fetchmail will not be fixed.

       Fetchmail cannot handle configurations where you have multiple accounts that use the  same
       server name and the same login. Any user@server combination must be unique.

       The  assumptions  that the DNS and in particular the checkalias options make are not often
       sustainable. For instance, it has become uncommon for an MX server to be a  POP3  or  IMAP
       server at the same time. Therefore the MX lookups may go away in a future release.

       The mda and plugin options interact badly.  In order to collect error status from the MDA,
       fetchmail has to change its normal signal handling so that dead plugin  processes  do  not
       get  reaped  until  the  end of the poll cycle.  This can cause resource starvation if too
       many zombies accumulate.  So either do not deliver to a MDA using plugins  or  risk  being
       overrun by an army of undead.

       The  --interface  option  does  not support IPv6 and it is doubtful if it ever will, since
       there is no portable way to query interface IPv6 addresses.

       The RFC822 address parser used in multidrop mode  chokes  on  some  @-addresses  that  are
       technically  legal  but bizarre.  Strange uses of quoting and embedded comments are likely
       to confuse it.

       In a message with multiple envelope headers, only the last one processed will  be  visible
       to fetchmail.

       Use  of  some of these protocols requires that the program send unencrypted passwords over
       the TCP/IP connection to the mail server.  This creates a risk  that  name/password  pairs
       might  be snaffled with a packet sniffer or more sophisticated monitoring software.  Under
       Linux and FreeBSD, the --interface option can be used to restrict polling to  availability
       of a specific interface device with a specific local or remote IP address, but snooping is
       still possible if (a) either host has a network device that can be opened  in  promiscuous
       mode,  or  (b) the intervening network link can be tapped.  We recommend the use of ssh(1)
       tunnelling to not only shroud your passwords but encrypt the entire conversation.

       Use of the %F or %T escapes in an mda option could open a security hole, because they pass
       text  manipulable  by  an  attacker  to  a  shell command.  Potential shell characters are
       replaced by '_' before execution.  The hole is further reduced by the fact that  fetchmail
       temporarily  discards  any  set-uid  privileges  it  may  have while running the MDA.  For
       maximum safety, however, do not use an mda command containing %F or %T when  fetchmail  is
       run from the root account itself.

       Fetchmail's  method  of  sending  bounces  due to errors or spam-blocking and spam bounces
       requires that port 25 of localhost be available for sending mail via SMTP.

       If you modify ~/.fetchmailrc while a background instance is running and break the  syntax,
       the  background  instance will die silently.  Unfortunately, it cannot die noisily because
       we do not yet know whether syslog should be enabled.   On  some  systems,  fetchmail  dies
       quietly  even  if  there is no syntax error; this seems to have something to do with buggy
       terminal ioctl code in the kernel.

       The -f - option (reading a configuration from  stdin)  is  incompatible  with  the  plugin

       The 'principal' option only handles Kerberos IV, not V.

       Interactively  entered  passwords are truncated after 63 characters. If you really need to
       use a longer password, you will have to use a configuration file.

       A backslash as the last character of a configuration file will  be  flagged  as  a  syntax
       error rather than ignored.

       The BSMTP error handling is virtually nonexistent and may leave broken messages behind.

       Send   comments,   bug   reports,  gripes,  and  the  like  to  the  fetchmail-devel  list

       An fetchmail FAQ (in HTML form)  ⟨⟩  is
       available at the fetchmail home page, it should also accompany your installation.


       Fetchmail  is  currently  maintained by Matthias Andree and Rob Funk with major assistance
       from Sunil Shetye (for code) and Rob MacGregor (for the mailing lists).

       Most of the code is from Eric S. Raymond ⟨⟩.  Too  many  other
       people to name here have contributed code and patches.

       This    program   is   descended   from   and   replaces   popclient,   by   Carl   Harris
       ⟨⟩; the internals have become quite  different,  but  some  of  its
       interface design is directly traceable to that ancestral program.

       This  manual  page  has  been  improved  by Matthias Andree, R. Hannes Beinert, and Héctor


       README,       README.SSL,        README.SSL-SERVER,        The        Fetchmail        FAQ
       ⟨⟩,  mutt(1),  elm(1),  mail(1), sendmail(8),
       popd(8),  imapd(8),  netrc(5),  the  fetchmail  home  page  ⟨⟩,
       (alternative   URI)   ⟨⟩;   the   maildrop   home   page.


       Note that this list is just a collection of references and  not  a  statement  as  to  the
       actual protocol conformance or requirements in fetchmail.

            RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985, RFC 2554.

            RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.

            RFC 937

            RFC  1081,  RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC 1957, RFC 2195, RFC

            RFC 1939.

            RFC 1081, RFC 1225.

            RFC 1176, RFC 1732.

            RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177, RFC 2683.

            RFC 1985.

            RFC 2645.

       OTP: RFC 1938.

            RFC 2033.

            RFC  1508,  RFC  1734,  Generic  Security  Service  Application   Program   Interface
            (GSSAPI)/Kerberos/Simple  Authentication  and  Security  Layer  (SASL)  Service Names

       TLS: RFC 2595.