maildropex(7)

NAME

   maildropex - maildrop filtering language examples

SYNOPSIS

   $HOME/.mailfilter, $HOME/.mailfilters/*

DESCRIPTION

   If $HOME/.mailfilter exists, filtering instructions in this file will
   be carried out prior to delivering the message. The filtering
   instructions may instruct maildrop to discard the message, save the
   message in a different mailbox, or forward the message to another
   address. If $HOME/.mailfilter does not exist, or does not provide
   explicit delivery instructions, maildrop delivers the message to the
   user's system mailbox.

   The files in $HOME/.mailfilters are used when maildrop is invoked in
   embedded mode.

EXAMPLES

   Take all mail that's sent to the 'auto' mailing list, and save it in
   Mail/auto. The 'auto' mailing list software adds a "Delivered-To:
   auto@domain.com" header to all messages:

       if (/^Delivered-To: *auto@domain\.com$/)
           to Mail/auto

   After the to command delivers the message, maildrop automatically stops
   filtering and terminates without executing the subsequent instructions
   in the filter file.

   Take all mail from <boss@domain.com> about the current project status,
   save it in Mail/project, then forward a copy to John:

       if (/^From: *boss@domain\.com/ \
           && /^Subject:.*[:wbreak:]project status[:wbreak:]/)
       {
           cc "!john"
           to Mail/project
       }

   Note that it is necessary to use a backslash in order to continue the
   if statement on the next line.

   Keep copies of the last 50 messages that you received in the maildir
   directory 'backup'. NOTE: 'backup' must be a maildir directory, not a
   mailbox. You can create a maildir using the maildirmake command.

       cc backup
       `cd backup/new && rm -f dummy \`ls -t | sed -e 1,50d\``

   Put this at the beginning of your filter file, before any other
   filtering instructions. This is a good idea to have when you are
   learning maildrop. If you make a mistake and accidentally delete a
   message, you can recover it from the backup/new subdirectory.

   Save messages that are at least 100 lines long (approximately) into
   Mail/IN.Large::

            if ( $LINES > 100 )
               to Mail/IN.Large

   Send messages from the auto mailing list to the program 'archive',
   using a lock file to make sure that only one instance of the archive
   program will be running at the same time:

            if (/^Delivered-To: *auto@domain\.com$/)
               dotlock "auto.lock" {

                      to "|archive"
               }

   Check if the Message-ID: header in the message is identical to the same
   header that was recently seen. Discard the message if it is, otherwise
   continue to filter the message:

       `reformail -D 8000 duplicate.cache`
       if ( $RETURNCODE == 0 )
           exit

   The reformail[1] command maintains a list of recently seen Message-IDs
   in the file duplicate.cache.

       Note
       Unlike a similar feature in the formail command, reformail[1] takes
       care of locking the file, so it's not necessary to implement your
       own locking mechanism for this option.

   Here's a more complicated example. This fragment is intended to go
   right after the message has been filtered according to your regular
   rules, and just before the message should be saved in your mailbox:

       cc $DEFAULT
       xfilter "reformail -r -t"
       /^To:.*/
       getaddr($MATCH) =~ /^.*/;

       MATCH=tolower($MATCH)
       flock "vacation.lock" {
               `fgrep -iqx "$MATCH" vacation.lst 2>/dev/null || { \
                         echo "$MATCH" >>vacation.lst ; \
                         exit 1 ; \
                     } `
       }
       if ( $RETURNCODE == 0 )
          exit
       to "| ( cat - ; echo ''; cat vacation.msg) | $SENDMAIL"

   This code maintains a list of everyone who sent you mail in the file
   called vacation.lst. When a message is received from anyone that is not
   already on the list, the address is added to the list, and the contents
   of the file vacation.msg are mailed back to the sender. This is
   intended to reply notify people that you will not be answering mail for
   a short period of time.

   The first statement saves the original message in your regular mailbox.
   Then, xfilter[2] is used to generate an autoreply header to the sender.
   The To: header in the autoreply - which was the sender of the original
   message - is extracted, and the getaddr[3] function is used to strip
   the person's name, leaving the address only. The file vacation.lst is
   checked, using a lock file to guarantee atomic access and update
   (overkill, probably). Note that the backslashes are required.

   If the address is already in the file, maildrop exits, otherwise the
   contents of vacation.msg are appended to the autoreply header, and
   mailed out.

       Note
       An easier to make a vacation script is with mailbot(1)[4].

   Here's a version of the vacation script that uses a GDBM database file
   instead. The difference between this script and the previous script is
   that the previous script will send a vacation message to a given E-mail
   address only once. The following script will store the time that the
   vacation message was sent in the GDBM file. If it's been at least a
   week since the vacation message has been sent to the given address,
   another vacation message will be sent.

   Even though a GDBM database file is used, locking is still necessary
   because the GDBM library does not allow more than one process to open
   the same database file for writing:

       cc $DEFAULT
       xfilter "reformail -r -t"
       /^To:.*/
       getaddr($MATCH) =~ /^.*/;
       MATCH=tolower($MATCH)
       flock "vacation.lock" {
           current_time=time;
           if (gdbmopen("vacation.dat", "C") == 0)
           {
              if ( (prev_time=gdbmfetch($MATCH)) ne "" && \
                    $prev_time >= $current_time - 60 * 60 * 24 * 7)
              {
                  exit
              }
              gdbmstore($MATCH, $current_time)
              gdbmclose
           }
       }
       to "| ( cat - ; echo ''; cat vacation.msg) | $SENDMAIL"

   This script requires that maildrop must be compiled with GDBM support
   enabled, which is done by default if GDBM libraries are present.

   After you return from vacation, you can use a simple Perl script to
   obtain a list of everyone who sent you mail (of course, that can also
   be determined by examining your mailbox).

SEE ALSO

   maildrop(1)[5], maildropfilter(7)[6], reformail(1)[1], mailbot(1)[4],
   egrep(1), grep(1), sendmail(8).

AUTHOR

   Sam Varshavchik
       Author

NOTES

    1. reformail
       http://www.courier-mta.org/maildrop/reformail.html

    2. xfilter
       http://www.courier-mta.org/maildrop/maildropfilter.html#xfilter

    3. getaddr
       http://www.courier-mta.org/maildrop/maildropfilter.html#getaddr

    4. mailbot(1)
       http://www.courier-mta.org/maildrop/mailbot.html

    5. maildrop(1)
       http://www.courier-mta.org/maildrop/maildrop.html

    6. maildropfilter(7)
       http://www.courier-mta.org/maildrop/maildropfilter.html

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