Provided by: postfix_2.2.10-1_i386 bug

NAME

       local - Postfix local mail delivery

SYNOPSIS

       local [generic Postfix daemon options]

DESCRIPTION

       The  local(8) daemon processes delivery requests from the Postfix queue
       manager to deliver mail to local  recipients.   Each  delivery  request
       specifies  a  queue file, a sender address, a domain or host to deliver
       to, and one or more recipients.  This program expects to  be  run  from
       the master(8) process manager.

       The  local(8)  daemon  updates  queue  files  and  marks  recipients as
       finished, or it informs the queue manager that delivery should be tried
       again  at  a  later  time.  Delivery  status  reports  are  sent to the
       bounce(8), defer(8) or trace(8) daemon as appropriate.

SYSTEM-WIDE AND USER-LEVEL ALIASING

       The system administrator can set up one or more  system-wide  sendmail-
       style alias databases.  Users can have sendmail-style ~/.forward files.
       Mail for name is delivered  to  the  alias  name,  to  destinations  in
       ~name/.forward,  to  the  mailbox owned by the user name, or it is sent
       back as undeliverable.

       The system administrator can specify a comma/space  separated  list  of
       ~/.forward like files through the forward_path configuration parameter.
       Upon delivery, the local delivery agent tries each pathname in the list
       until a file is found.

       Delivery  via  ~/..forward  files  is  done  with the privileges of the
       recipient.  Thus,  ~/.forward  like  files  must  be  readable  by  the
       recipient,   and   their  parent  directory  needs  to  have  "execute"
       permission for the recipient.

       The  forward_path  parameter  is  subject  to  interpolation  of  $user
       (recipient   username),   $home   (recipient  home  directory),  $shell
       (recipient shell), $recipient (complete recipient address),  $extension
       (recipient  address  extension),  $domain  (recipient  domain),  $local
       (entire recipient  address  localpart)  and  $recipient_delimiter.  The
       forms  ${name?value}  and  ${name:value}  expand conditionally to value
       when $name is (is not)  defined.   Characters  that  may  have  special
       meaning  to  the shell or file system are replaced by underscores.  The
       list   of    acceptable    characters    is    specified    with    the
       forward_expansion_filter configuration parameter.

       An  alias  or  ~/.forward  file  may  list  any combination of external
       commands,  destination  file  names,  :include:  directives,  or   mail
       addresses.   See  aliases(5)  for a precise description. Each line in a
       user’s .forward file has the same syntax as the right-hand part  of  an
       alias.

       When  an  address is found in its own alias expansion, delivery is made
       to the user instead. When a user is listed in the user’s own ~/.forward
       file,  delivery  is  made  to  the  user’s  mailbox  instead.  An empty
       ~/.forward file means do not forward mail.

       In order to prevent the mail system from using up unreasonable  amounts
       of  memory,  input records read from :include: or from ~/.forward files
       are broken up into chunks of length line_length_limit.

       While expanding aliases, ~/.forward  files,  and  so  on,  the  program
       attempts  to  avoid  duplicate  deliveries.  The duplicate_filter_limit
       configuration parameter limits the number of remembered recipients.

MAIL FORWARDING

       For the sake of reliability, forwarded mail is re-submitted  as  a  new
       message,  so that each recipient has a separate on-file delivery status
       record.

       In order to stop mail forwarding loops  early,  the  software  adds  an
       optional   Delivered-To:  header  with  the  final  envelope  recipient
       address. If mail arrives for a recipient that is already  listed  in  a
       Delivered-To: header, the message is bounced.

MAILBOX DELIVERY

       The default per-user mailbox is a file in the UNIX mail spool directory
       (/var/mail/user or /var/spool/mail/user); the location can be specified
       with  the  mail_spool_directory configuration parameter. Specify a name
       ending in / for qmail-compatible maildir delivery.

       Alternatively, the per-user mailbox can be a file in  the  user’s  home
       directory  with  a  name  specified  via the home_mailbox configuration
       parameter. Specify a relative path name. Specify a name ending in / for
       qmail-compatible maildir delivery.

       Mailbox delivery can be delegated to an external command specified with
       the mailbox_command configuration parameter. The command executes  with
       the  privileges of the recipient user (exceptions: secondary groups are
       not enabled; in case of delivery as root, the command executes with the
       privileges of default_privs).

       Mailbox  delivery  can  be  delegated to alternative message transports
       specified in the master.cf file.  The  mailbox_transport  configuration
       parameter  specifies  a  message  transport  that is to be used for all
       local recipients, regardless of whether they  are  found  in  the  UNIX
       passwd  database.  The fallback_transport parameter specifies a message
       transport for  recipients  that  are  not  found  in  the  UNIX  passwd
       database.

       In  the  case  of  UNIX-style  mailbox  delivery,  the  local(8) daemon
       prepends a "From sender time_stamp" envelope header  to  each  message,
       prepends  an  X-Original-To: header with the recipient address as given
       to Postfix, prepends an optional Delivered-To: header  with  the  final
       envelope  recipient  address,  prepends  a Return-Path: header with the
       envelope sender address, prepends a > character to lines beginning with
       "From  ",  and  appends  an  empty  line.   The  mailbox  is locked for
       exclusive access while delivery is in progress. In case of problems, an
       attempt is made to truncate the mailbox to its original length.

       In  the case of maildir delivery, the local daemon prepends an optional
       Delivered-To:  header  with  the  final  envelope  recipient   address,
       prepends  an  X-Original-To: header with the recipient address as given
       to Postfix, and prepends a Return-Path: header with the envelope sender
       address.

EXTERNAL COMMAND DELIVERY

       The  allow_mail_to_commands  configuration parameter restricts delivery
       to external commands. The  default  setting  (alias,  forward)  forbids
       command destinations in :include: files.

       Optionally,  the  process  working  directory  is  changed  to the path
       specified with command_execution_directory  (Postfix  2.2  and  later).
       Failure to change directory causes mail to be deferred.

       The   command_execution_directory   parameter   value   is  subject  to
       interpolation of $user  (recipient  username),  $home  (recipient  home
       directory),  $shell  (recipient  shell), $recipient (complete recipient
       address), $extension (recipient address extension), $domain  (recipient
       domain),    $local    (entire    recipient   address   localpart)   and
       $recipient_delimiter.  The forms ${name?value} and ${name:value} expand
       conditionally to value when $name is (is not) defined.  Characters that
       may have special meaning to the shell or file system  are  replaced  by
       underscores.   The  list of acceptable characters is specified with the
       execution_directory_expansion_filter configuration parameter.

       The command is executed directly  where  possible.  Assistance  by  the
       shell  (/bin/sh on UNIX systems) is used only when the command contains
       shell magic characters, or when the command invokes  a  shell  built-in
       command.

       A limited amount of command output (standard output and standard error)
       is captured for inclusion with non-delivery status reports.  A  command
       is    forcibly    terminated   if   it   does   not   complete   within
       command_time_limit seconds.  Command exit status codes are expected  to
       follow the conventions defined in <sysexits.h>.

       A  limited  amount  of  message  context  is  exported  via environment
       variables. Characters that may have special meaning to  the  shell  are
       replaced   by  underscores.   The  list  of  acceptable  characters  is
       specified with the command_expansion_filter configuration parameter.

       SHELL  The recipient user’s login shell.

       HOME   The recipient user’s home directory.

       USER   The bare recipient name.

       EXTENSION
              The optional recipient address extension.

       DOMAIN The recipient address domain part.

       LOGNAME
              The bare recipient name.

       LOCAL  The entire recipient address localpart (text to the left of  the
              rightmost @ character).

       RECIPIENT
              The entire recipient address.

       SENDER The entire sender address.

       Additional   remote  client  information  is  made  available  via  the
       following environment variables:

       CLIENT_ADDRESS
              Remote client network address. Available as of Postfix 2.2.

       CLIENT_HELO
              Remote client EHLO command parameter. Available  as  of  Postfix
              2.2.

       CLIENT_HOSTNAME
              Remote client hostname. Available as of Postfix 2.2.

       CLIENT_PROTOCOL
              Remote client protocol. Available as of Postfix 2.2.

       SASL_METHOD
              SASL  authentication  method specified in the remote client AUTH
              command. Available as of Postfix 2.2.

       SASL_SENDER
              SASL sender address specified in the  remote  client  MAIL  FROM
              command. Available as of Postfix 2.2.

       SASL_USERNAME
              SASL  username  specified  in  the  remote  client AUTH command.
              Available as of Postfix 2.2.

       The PATH environment variable is always  reset  to  a  system-dependent
       default  path, and environment variables whose names are blessed by the
       export_environment configuration parameter are exported unchanged.

       The current working directory is the mail queue directory.

       The local(8) daemon prepends a "From sender time_stamp" envelope header
       to  each  message, prepends an X-Original-To: header with the recipient
       address as given to Postfix, prepends an optional Delivered-To:  header
       with  the  final  recipient  envelope  address, prepends a Return-Path:
       header with the sender envelope address, and appends no empty line.

EXTERNAL FILE DELIVERY

       The delivery format depends on the destination  filename  syntax.   The
       default  is to use UNIX-style mailbox format.  Specify a name ending in
       / for qmail-compatible maildir delivery.

       The allow_mail_to_files configuration parameter restricts  delivery  to
       external  files.  The  default  setting  (alias,  forward) forbids file
       destinations in :include: files.

       In the  case  of  UNIX-style  mailbox  delivery,  the  local(8)  daemon
       prepends  a  "From  sender time_stamp" envelope header to each message,
       prepends an X-Original-To: header with the recipient address  as  given
       to  Postfix,  prepends  an optional Delivered-To: header with the final
       recipient envelope address, prepends a > character to  lines  beginning
       with  "From  ", and appends an empty line.  The envelope sender address
       is available in the Return-Path: header.  When  the  destination  is  a
       regular  file,  it  is locked for exclusive access while delivery is in
       progress. In case of problems, an attempt is made to truncate a regular
       file to its original length.

       In  the case of maildir delivery, the local daemon prepends an optional
       Delivered-To: header with the final  envelope  recipient  address,  and
       prepends  an  X-Original-To: header with the recipient address as given
       to Postfix.  The envelope sender address is available  in  the  Return-
       Path: header.

ADDRESS EXTENSION

       The  optional recipient_delimiter configuration parameter specifies how
       to separate address extensions from local recipient names.

       For example, with "recipient_delimiter  =  +",  mail  for  name+foo  is
       delivered  to  the  alias  name+foo  or  to  the  alias  name,  to  the
       destinations listed in ~name/.forward+foo or in ~name/.forward, to  the
       mailbox owned by the user name, or it is sent back as undeliverable.

       In  all  cases  the local(8) daemon prepends an optional ‘Delivered-To:
       header line with the final recipient address.

DELIVERY RIGHTS

       Deliveries to external files and external commands are  made  with  the
       rights  of the receiving user on whose behalf the delivery is made.  In
       the absence of a user context,  the  local(8)  daemon  uses  the  owner
       rights  of  the :include: file or alias database.  When those files are
       owned by the superuser, delivery is made with the rights specified with
       the default_privs configuration parameter.

STANDARDS

       RFC 822 (ARPA Internet Text Messages)

DIAGNOSTICS

       Problems  and transactions are logged to syslogd(8).  Corrupted message
       files are marked so that the queue manager can move them to the corrupt
       queue afterwards.

       Depending   on   the  setting  of  the  notify_classes  parameter,  the
       postmaster is notified of bounces and of other trouble.

SECURITY

       The local(8) delivery agent needs a dual personality 1) to  access  the
       private  Postfix  queue  and  IPC  mechanisms,  2)  to  impersonate the
       recipient and deliver to recipient-specified files or commands.  It  is
       therefore security sensitive.

       The  local(8)  delivery agent disallows regular expression substitution
       of $1 etc. in alias_maps, because that would open a security hole.

       The local(8) delivery agent will silently ignore requests  to  use  the
       proxymap(8)  server  within  alias_maps. Instead it will open the table
       directly.  Before Postfix version 2.2, the local(8) delivery agent will
       terminate with a fatal error.

BUGS

       For  security reasons, the message delivery status of external commands
       or of external files is never checkpointed to file. As  a  result,  the
       program  may  occasionally  deliver  more  than  once  to  a command or
       external file. Better safe than sorry.

       Mutually-recursive aliases or ~/.forward files are not detected  early.
       The  resulting  mail  forwarding  loop  is  broken  by  the  use of the
       Delivered-To: message header.

CONFIGURATION PARAMETERS

       Changes to main.cf are picked up automatically, as  local(8)  processes
       run for only a limited amount of time. Use the command "postfix reload"
       to speed up a change.

       The text below provides only a parameter summary. See  postconf(5)  for
       more details including examples.

COMPATIBILITY CONTROLS

       biff (yes)
              Whether or not to use the local biff service.

       expand_owner_alias (no)
              When  delivering  to  an  alias  "aliasname" that has an "owner-
              aliasname" companion alias, set the envelope sender  address  to
              the expansion of the "owner-aliasname" alias.

       owner_request_special (yes)
              Give  special  treatment  to owner-listname and listname-request
              address  localparts:  don’t  split  such  addresses   when   the
              recipient_delimiter is set to "-".

       sun_mailtool_compatibility (no)
              Obsolete SUN mailtool compatibility feature.

DELIVERY METHOD CONTROLS

       The  precedence  of  local(8)  delivery  methods  from  high to low is:
       aliases,  .forward  files,   mailbox_transport,   mailbox_command_maps,
       mailbox_command, home_mailbox, mail_spool_directory, fallback_transport
       and luser_relay.

       alias_maps (seepostconf -doutput)
              The alias databases that are used for local(8) delivery.

       forward_path (seepostconf -doutput)
              The local(8) delivery agent search list for finding  a  .forward
              file with user-specified delivery methods.

       mailbox_transport (empty)
              Optional  message  delivery transport that the local(8) delivery
              agent should use for mailbox delivery to all  local  recipients,
              whether or not they are found in the UNIX passwd database.

       mailbox_command_maps (empty)
              Optional  lookup  tables with per-recipient external commands to
              use for local(8) mailbox delivery.

       mailbox_command (empty)
              Optional external  command  that  the  local(8)  delivery  agent
              should use for mailbox delivery.

       home_mailbox (empty)
              Optional  pathname  of  a  mailbox  file  relative to a local(8)
              user’s home directory.

       mail_spool_directory (seepostconf -doutput)
              The directory where local(8) UNIX-style mailboxes are kept.

       fallback_transport (empty)
              Optional message delivery transport that the  local(8)  delivery
              agent  should use for names that are not found in the aliases(5)
              database or in the UNIX passwd database.

       luser_relay (empty)
              Optional catch-all destination for unknown local(8)  recipients.

       Available in Postfix version 2.2 and later:

       command_execution_directory (empty)
              The  local(8)  delivery  agent working directory for delivery to
              external command.

MAILBOX LOCKING CONTROLS

       deliver_lock_attempts (20)
              The maximal number of attempts to acquire an exclusive lock on a
              mailbox file or bounce(8) logfile.

       deliver_lock_delay (1s)
              The  time  between  attempts  to  acquire an exclusive lock on a
              mailbox file or bounce(8) logfile.

       stale_lock_time (500s)
              The time after which  a  stale  exclusive  mailbox  lockfile  is
              removed.

       mailbox_delivery_lock (seepostconf -doutput)
              How  to  lock  a  UNIX-style  local(8) mailbox before attempting
              delivery.

RESOURCE AND RATE CONTROLS

       command_time_limit (1000s)
              Time limit for delivery to external commands.

       duplicate_filter_limit (1000)
              The maximal  number  of  addresses  remembered  by  the  address
              duplicate  filter  for aliases(5) or virtual(5) alias expansion,
              or for showq(8) queue displays.

       local_destination_concurrency_limit (2)
              The maximal number of parallel deliveries  via  the  local  mail
              delivery    transport    to    the    same    recipient    (when
              "local_destination_recipient_limit = 1") or the  maximal  number
              of   parallel   deliveries   to  the  same  local  domain  (when
              "local_destination_recipient_limit > 1").

       local_destination_recipient_limit (1)
              The maximal number of recipients per message  delivery  via  the
              local mail delivery transport.

       mailbox_size_limit (51200000)
              The  maximal  size of any local(8) individual mailbox or maildir
              file, or zero (no limit).

SECURITY CONTROLS

       allow_mail_to_commands (alias, forward)
              Restrict local(8) mail delivery to external commands.

       allow_mail_to_files (alias, forward)
              Restrict local(8) mail delivery to external files.

       command_expansion_filter (seepostconf -doutput)
              Restrict the characters that the local(8) delivery agent  allows
              in $name expansions of $mailbox_command.

       default_privs (nobody)
              The  default  rights  used  by  the  local(8) delivery agent for
              delivery to external file or command.

       forward_expansion_filter (seepostconf -doutput)
              Restrict the characters that the local(8) delivery agent  allows
              in $name expansions of $forward_path.

       Available in Postfix version 2.2 and later:

       execution_directory_expansion_filter (seepostconf -doutput)
              Restrict  the characters that the local(8) delivery agent allows
              in $name expansions of $command_execution_directory.

MISCELLANEOUS CONTROLS

       config_directory (seepostconf -doutput)
              The default  location  of  the  Postfix  main.cf  and  master.cf
              configuration files.

       daemon_timeout (18000s)
              How  much  time  a  Postfix  daemon process may take to handle a
              request before it is terminated by a built-in watchdog timer.

       export_environment (seepostconf -doutput)
              The list of environment variables that a  Postfix  process  will
              export to non-Postfix processes.

       ipc_timeout (3600s)
              The  time  limit  for  sending  or receiving information over an
              internal communication channel.

       local_command_shell (empty)
              Optional shell program  for  local(8)  delivery  to  non-Postfix
              command.

       max_idle (100s)
              The  maximum  amount of time that an idle Postfix daemon process
              waits for the next service request before exiting.

       max_use (100)
              The maximal number  of  connection  requests  before  a  Postfix
              daemon process terminates.

       prepend_delivered_header (command, file, forward)
              The   message  delivery  contexts  where  the  Postfix  local(8)
              delivery agent prepends a Delivered-To:  message header.

       process_id (read-only)
              The process ID of a Postfix command or daemon process.

       process_name (read-only)
              The process name of a Postfix command or daemon process.

       propagate_unmatched_extensions (canonical, virtual)
              What address lookup tables copy an address  extension  from  the
              lookup key to the lookup result.

       queue_directory (seepostconf -doutput)
              The location of the Postfix top-level queue directory.

       recipient_delimiter (empty)
              The   separator   between  user  names  and  address  extensions
              (user+foo).

       require_home_directory (no)
              Whether or not a local(8) recipient’s home directory must  exist
              before mail delivery is attempted.

       syslog_facility (mail)
              The syslog facility of Postfix logging.

       syslog_name (postfix)
              The  mail  system  name that is prepended to the process name in
              syslog  records,  so  that   "smtpd"   becomes,   for   example,
              "postfix/smtpd".

FILES

       The following are examples; details differ between systems.
       $HOME/.forward, per-user aliasing
       /etc/aliases, system-wide alias database
       /var/spool/mail, system mailboxes

SEE ALSO

       qmgr(8), queue manager
       bounce(8), delivery status reports
       newaliases(1), create/update alias database
       postalias(1), create/update alias database
       aliases(5), format of alias database
       postconf(5), configuration parameters
       master(5), generic daemon options
       syslogd(8), system logging

LICENSE

       The Secure Mailer license must be distributed with this software.

HISTORY

       The  Delivered-To: message header appears in the qmail system by Daniel
       Bernstein.

       The maildir structure appears in the qmail system by Daniel  Bernstein.

AUTHOR(S)

       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA

                                                                      LOCAL(8)