Provided by: procmail_3.24-1_amd64 bug

NAME

       formail - mail (re)formatter

SYNOPSIS

       formail [+skip] [-total] [-bczfrktedqBY] [-p prefix]
            [-D maxlen idcache]
            [-l folder]
            [-x headerfield] [-X headerfield]
            [-a headerfield] [-A headerfield]
            [-i headerfield] [-I headerfield]
            [-u headerfield] [-U headerfield]
            [-R oldfield newfield]
            [-n [maxprocs ]] [-m minfields] [-s [command [arg ...]]]
       formail -v

DESCRIPTION

       formail  is  a  filter that can be used to force mail into mailbox format, perform `From '
       escaping, generate auto-replying headers, do simple header munging/extracting or split  up
       a  mailbox/digest/articles  file.   The  mail/mailbox/article contents will be expected on
       stdin.

       If formail is supposed to determine the sender of the mail, but is unable to find any,  it
       will substitute `foo@bar'.

       If formail is started without any command line options, it will force any mail coming from
       stdin into mailbox format and will escape all bogus `From ' lines with a `>'.

OPTIONS

       -v   Formail will print its version number and exit.

       -b   Don't escape any bogus mailbox headers (i.e., lines starting with `From ').

       -p prefix
            Define a different quotation prefix.  If unspecified it defaults to `>'.

       -Y   Assume traditional Berkeley mailbox format, ignoring any Content-Length: fields.

       -c   Concatenate continued fields in the header.  Might be convenient when  postprocessing
            mail with standard (line oriented) text utilities.

       -z   Ensure  a whitespace exists between field name and content.  Zap fields which contain
            only a single whitespace character.  Zap leading and trailing  whitespace  on  fields
            extracted with -x.

       -f   Force  formail  to  simply  pass along any non-mailbox format (i.e., don't generate a
            `From ' line as the first line).

       -r   Generate an auto-reply header.  This will normally throw away all the existing fields
            (except  X-Loop:)  in  the  original  message, fields you wish to preserve need to be
            named using the -i option.  If you use this option in conjunction with  -k,  you  can
            prevent the body from being `escaped' by also specifying -b.

       -k   When  generating  the  auto-reply  header or when extracting fields, keep the body as
            well.

       -t   Trust the sender to have used a valid return address  in  his  header.   This  causes
            formail  to  select  the  header sender instead of the envelope sender for the reply.
            This option should be used when generating auto-reply headers from news  articles  or
            when the sender of the message is expecting a reply.

       -s   The  input will be split up into separate mail messages, and piped into a program one
            by one (a new program is started for every part).  -s  has  to  be  the  last  option
            specified,  the  first argument following it is expected to be the name of a program,
            any other arguments will be passed along to  it.   If  you  omit  the  program,  then
            formail will simply concatenate the split mails on stdout again.  See FILENO.

       -n [maxprocs]
            Tell formail not to wait for every program to finish before starting the next (causes
            splits to be processed in parallel).  Maxprocs optionally specifies an upper limit on
            the number of concurrently running processes.

       -e   Do  not  require  empty lines to be preceding the header of a new message (i.e.,  the
            messages could start on every line).

       -d   Tell formail that the messages it is supposed to split need not be in strict  mailbox
            format  (i.e., allows you to split digests/articles or non-standard mailbox formats).
            This disables recognition of the Content-Length: field.

       -l folder
            Generate a log summary in the same style as procmail.  This includes the entire "From
            "  line, the Subject: header field, the folder, and the size of the message in bytes.
            The mailstat command can be used to summarize logs in this format.

       -B   Makes formail assume that it is splitting up a BABYL rmail file.

       -m minfields
            Allows you to specify the number of consecutive headerfields formail  needs  to  find
            before it decides it found the start of a new message, it defaults to 2.

       -q   Tells  formail  to (still detect but) be quiet about write errors, duplicate messages
            and mismatched Content-Length: fields.  This option is on  by  default,  to  make  it
            display the messages use -q-.

       -D maxlen idcache
            Formail  will  detect  if the Message-ID of the current message has already been seen
            using an idcache file of approximately maxlen size.  If not splitting, it will return
            success  if  a  duplicate has been found.  If splitting, it will not output duplicate
            messages.  If used in conjunction with -r, formail will look at the mail  address  of
            the envelope sender instead at the Message-ID.

       -x headerfield
            Extract the contents of this headerfield from the header.  Line continuations will be
            left intact; if you want the value on a single line then  you'll  also  need  the  -c
            option.

       -X headerfield
            Same as -x, but also preserves/includes the field name.

       -a headerfield
            Append  a  custom  headerfield  onto the header; but only if a similar field does not
            exist yet.  If you specify either one of  the  field  names  Message-ID:  or  Resent-
            Message-ID:  with  no  field contents, then formail will generate a unique message-ID
            for you.

       -A headerfield
            Append a custom headerfield onto the header in any case.

       -i headerfield
            Same as -A, except that any existing similar fields  are  renamed  by  prepending  an
            ``Old-''  prefix.   If  headerfield  consists  only  of  a field-name, it will not be
            appended.

       -I headerfield
            Same as -i,  except  that  any  existing  similar  fields  are  simply  removed.   If
            headerfield consists only of a field-name, it effectively deletes the field.

       -u headerfield
            Make  the  first  occurrence  of  this  field  unique, and thus delete all subsequent
            occurrences of it.

       -U headerfield
            Make the last occurrence  of  this  field  unique,  and  thus  delete  all  preceding
            occurrences of it.

       -R oldfield newfield
            Renames all occurrences of the fieldname oldfield into newfield.

       +skip
            Skip the first skip messages while splitting.

       -total
            Output at most total messages while splitting.

NOTES

       When  renaming,  removing, or extracting fields, partial fieldnames may be used to specify
       all fields that start with the specified value.

       By default, when generating an auto-reply header formail selects the envelope sender  from
       the  input  message.   This  is  correct for vacation messages and other automatic replies
       regarding the routing or delivery of the original message.  If the sender is  expecting  a
       reply  or the reply is being generated in response to the contents of the original message
       then the -t option should be used.

       RFC822, the original standard governing the format of  Internet  mail  messages,  did  not
       specify   whether  Resent  header  fields  (those  that  begin  with  `Resent-',  such  as
       `Resent-From:') should be considered when generating a reply.  Since then, the recommended
       usage  of  the Resent headers has evolved to consider them as purely informational and not
       for use when generating a reply.  This has been codified  in  RFC2822,  the  new  Internet
       Message Format standard, which states in part:

              Resent  fields  are used to identify a message as having been reintroduced into the
              transport system by a user.  The purpose of using resent  fields  is  to  have  the
              message  appear  to the final recipient as if it were sent directly by the original
              sender, with all of the original fields remaining the same....They MUST NOT be used
              in the normal processing of replies or other such automatic actions on messages.

       While  formail  now  ignores  Resent  headers  when generating header replies, versions of
       formail prior to 3.14 gave such headers a high precedence.  If the old behavior is  needed
       for  established  applications  it can be specified by calling formail with the option `-a
       Resent-' in addition to the -r and -t options.  This usage is deprecated and should not be
       used in new applications.

ENVIRONMENT

       FILENO
            While  splitting,  formail  assigns the message number currently being output to this
            variable.  By presetting FILENO, you can change the initial message number being used
            and  the width of the zero-padded output.  If FILENO is unset it will default to 000.
            If FILENO is non-empty and does not contain a number, FILENO generation is disabled.

EXAMPLES

       To split up a digest one usually uses:
              formail +1 -ds >>the_mailbox_of_your_choice
       or
              formail +1 -ds procmail

       To remove all Received: fields from the header:
              formail -I Received:

       To remove all fields except From: and Subject: from the header:
              formail -k -X From: -X Subject:

       To supersede the Reply-To: field in a header you could use:
              formail -i "Reply-To: foo@bar"

       To convert a non-standard mailbox file into a standard mailbox file you can use:
              formail -ds <old_mailbox >>new_mailbox

       Or, if you have a very tolerant mailer:
              formail -a Date: -ds <old_mailbox >>new_mailbox

       To extract the header from a message:
              formail -X ""
       or
              sed -e '/^$/ q'

       To extract the body from a message:
              formail -I ""
       or
              sed -e '1,/^$/ d'

SEE ALSO

       mail(1), sendmail(8), procmail(1), sed(1), sh(1), RFC822, RFC2822, RFC1123

DIAGNOSTICS

       Can't fork             Too many processes on this machine.

       Content-Length: field exceeds actual length by nnn bytes
                              The Content-Length: field in the header specified a length that was
                              longer  than the actual body.  This causes this message to absorb a
                              number of subsequent messages following it in the same mailbox.

       Couldn't write to stdout
                              The program that formail was trying to pipe into didn't accept  all
                              the  data  formail sent to it; this diagnostic can be suppressed by
                              the -q option.

       Duplicate key found: x The Message-ID or sender  x  in  this  message  was  found  in  the
                              idcache; this diagnostic can be suppressed by the -q option.

       Failed to execute "x"  Program not in path, or not executable.

       File table full        Too many open files on this machine.

       Invalid field-name: "x"
                              The specified field-name "x" contains control characters, or cannot
                              be a partial field-name for this option.

WARNINGS

       You can save yourself and others a lot of grief if you try to avoid using  this  autoreply
       feature  on  mails  coming  through mailinglists.  Depending on the format of the incoming
       mail (which in turn depends on both the original sender's mail agent and  the  mailinglist
       setup) formail could decide to generate an autoreply header that replies to the list.

       In the tradition of UN*X utilities, formail will do exactly what you ask it to, even if it
       results in a non-RFC822 compliant message.  In particular, formail will let  you  generate
       header  fields  whose  name ends in a space instead of a colon.  While this is correct for
       the leading `From ' line, that line is not a header field so much as the message separator
       for  the  mbox mailbox format.  Multiple occurrences of such a line or any other colonless
       header field will be considered by many mail programs, including formail  itself,  as  the
       beginning  of  a new message.  Others will consider the message to be corrupt.  Because of
       this, you should not use the -i option with the `From '  line  as  the  resulting  renamed
       line,  `Old-From  ',  will  probably  not do what you want it to.  If you want to save the
       original `From ' line, rename it with the -R option to a legal header field  such  as  `X-
       From_:'.

BUGS

       When  formail  has to generate a leading `From ' line it normally will contain the current
       date.  If formail is given the option `-a Date:', it will use the date  from  the  `Date:'
       field  in  the header (if present).  However, since formail copies it verbatim, the format
       will differ from that expected by most mail readers.

       If formail is instructed to delete or rename  the  leading  `From  '  line,  it  will  not
       automatically  regenerate  it  as  usual.  To force formail to regenerate it in this case,
       include -a 'From '.

       If formail is not called as the first program in a pipe and it is told  to  split  up  the
       input  in  several messages, then formail will not terminate until the program it receives
       the input from closes its output or terminates itself.

       If formail is instructed to generate an autoreply mail, it will never put  more  than  one
       address in the `To:' field.

MISCELLANEOUS

       Formail is eight-bit clean.

       When  formail  has to determine the sender's address, every RFC822 conforming mail address
       is allowed.  Formail will always strip down the address  to  its  minimal  form  (deleting
       excessive comments and whitespace).

       The regular expression that is used to find `real' postmarks is:
              "\n\nFrom [\t ]*[^\t\n ]+[\t ]+[^\n\t ]"

       If a Content-Length: field is found in a header, formail will copy the number of specified
       bytes in the body verbatim before resuming the regular  scanning  for  message  boundaries
       (except when splitting digests or Berkeley mailbox format is assumed).

       Any  header  lines immediately following the leading `From ' line that start with `>From '
       are considered to be a continuation of the `From ' line.   If  instructed  to  rename  the
       `From  '  line,  formail  will  change each leading `>' into a space, thereby transforming
       those lines into normal RFC822 continuations.

NOTES

       Calling up formail with the -h or -? options will cause it to display a command-line  help
       page.

SOURCE

       This  program  is  part  of  the  procmail  mail-processing-package  (v3.24)  available at
       http://www.procmail.org/ or ftp.procmail.org in pub/procmail/.

MAILINGLIST

       There exists a mailinglist for questions relating to any program in the procmail package:
              <procmail-users@procmail.org>
                     for submitting questions/answers.
              <procmail-users-request@procmail.org>
                     for subscription requests.

       If you would like to stay  informed  about  new  versions  and  official  patches  send  a
       subscription request to
              procmail-announce-request@procmail.org
       (this is a readonly list).

AUTHORS

       Stephen R. van den Berg
              <srb@cuci.nl>

                                             BuGless                                   FORMAIL(1)