MAILDROPEX(7)               Double Precision, Inc.               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.

       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
           [set $man.base.url.for.relative.links]/reformail.html

        2. xfilter
           [set $man.base.url.for.relative.links]/maildropfilter.html#xfilter

        3. getaddr
           [set $man.base.url.for.relative.links]/maildropfilter.html#getaddr

        4. mailbot(1)
           [set $man.base.url.for.relative.links]/mailbot.html

        5. maildrop(1)
           [set $man.base.url.for.relative.links]/maildrop.html

        6. maildropfilter(7)
           [set $man.base.url.for.relative.links]/maildropfilter.html



Courier Mail Server               04/04/2011                     MAILDROPEX(7)
