maildropex - examples of maildrop filtering language



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 direct 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 end up providing 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 the 'Mail/auto' mailbox. The 'auto' mailing list software adds a "Delivered-To: auto@domain.com" header to all messages submitted to the list:
     if (/^Delivered-To: *auto@domain\.com$/)
           to Mail/auto
After delivering the message via the "to" command, maildrop automatically stops filtering and terminates without executing any other instructions in the filter file.

Take all mail from 'boss@domain.com' about the current status of the project, save it in the folder "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 directory 'backup'. NOTE: 'backup' must be a maildir directory, not a mailbox. You can create a maildir using the maildirmake command. maildirmake comes with qmail, or if qmail is not installed, a substitute command is provided as part of the maildrop package.

     cc backup
     `cd backup/new && rm -f dummy \`ls -t | sed -e 1,50\``
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 this filtering language. 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 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) =~ /^.*/;
    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 provide a short acknowledge to 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 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() 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 contents of vacation.msg are appended to the autoreply header, and mailed out.

SEE ALSO

maildrop(1), maildropfilter(1), reformail(1), egrep(1), grep(1), sendmail(8), http://www.qmail.org