How to use procmail

[Martin Janzen <janzen@idacom.hp.com>]

"Damaged Justice" writes:
> Would some kind soul out there be willing to instruct a novice in the
> mysteries of procmail? I've finally decided to start killfiling my mail
> as well as my news.

A fine idea.  Procmail makes the Cypherpunks list infinitely more readable.


1) First, here's how to get it:

----------------------
A recent version can be picked up at various comp.sources.misc archives.
The latest version can be obtained directly from the ftp-archive at:

        amaru.informatik.rwth-aachen.de (137.226.112.31)

        as compressed tar file:         pub/unix/procmail.tar.Z         <100KB
        or in compressed shar format:   pub/unix/procmail.0?.Z
----------------------


2) Build the procmail program and install it in a suitable location.  I
have no idea what your familiarity with UNIX and C is; you may want to
have your sysadmin help you with this.  Alternatively, you could use
Alta Vista or equivalent to search for binaries for your system.


3) Create a file of procmail "recipes", which tell it how to process
your mail.  This file is called "$HOME/.procmailrc".  Mine begins like
this; fix up directory names as needed for your system:

-----------------------
#
# $HOME/.procmailrc  -  procmail recipe file
#
PATH=/usr/local/bin:/usr/ucb:/bin:/usr/bin:$HOME/bin/700o:$HOME/bin
ME=             janzen
HOME=           /Home/$ME
LOGFILE=        $HOME/.procmaillog
MAILDIR=        $HOME/Mail
ORGMAIL=        /usr/mail/$ME
DEFAULT=        $ORGMAIL
TMP=            $HOME/tmp
SENDMAIL=       /usr/lib/sendmail
TMPFILE=        $TMP/procmail.$$
LOCKFILE=       $HOME/Mail/.procmail

# toss out junk mail
:1
^Subject:.*unsubscribe
/dev/null

# sort mail from mailing lists into the proper folders
:1
cypherpunks
Cypherpunks
-----------------------

The last part sorts all mail whose header contains the word "cypherpunks"
into the folder $MAILDIR/Cypherpunks.  Now the fun part -- writing your
"recipes"!  You can get as specific as you want: 

-----------------------
# kill a particular thread
:2
^To:.*cypherpunks@toad.com
^Subject:.*Workers of the
/dev/null

# ignore a particular user
:2
cypherpunks
patrickbc@juno.com
/dev/null

# I haven't tried this one, but any subject with too many consecutive
# capitals is probably spam or worse.  Separate it out, but don't toss
# it just yet.
:2
cypherpunks
^Subject:.*[A-Z][A-Z][A-Z][A-Z][A-Z][A-Z]
ProbableSpam

# search the whole message body, not just the headers, for probable spam
:1HB
^dear friend
ProbableSpam

# put everything else in the incoming Cypherpunks mail folder
:1
^To:.*cypherpunks@toad.com
NewCypherpunksMail
-----------------------

Rules are evaluated in top-to-bottom order; first matching rule wins.
Anything not matched ends up in your usual $ORGMAIL folder.


4) Run your incoming mail through procmail.  To do this, most Unix systems
let you create a file called "$HOME/.forward" with the following contents
(including the quotes):

"| IFS=' '; /usr/local/bin/procmail -p"

(Replace "/usr/local/bin" with the directory in which you installed procmail.)


5) One thing to watch out for:  procmail is executed on the machine which
handles your mail.  If this machine has a different architecture than your
own machine, you must build procmail for the mail handling machine, not
your own.

Also, the permissions on your $HOME/.forward and $HOME/.procmailrc files
must be set so that they are readable on the mail handling machine.  If
your home directory is NFS-mounted, this should happen automatically;
otherwise, you may need to copy them to the mail handling machine manually.

Finally, the procmail process may not have your userid, so you must make
these files world-readable:

chmod 644 $HOME/.forward $HOME/.procmailrc

For the first day or two, check your $HOME/.procmaillog file frequently
to see whether there are any problems.  Check with your sysadmin to make
sure that your mail isn't ending up "all over the floor".  Send yourself
mail to test "recipes".


6) Once it's running smoothly, you can get fancy and run the following
shell script, which reads the $HOME/.procmaillog file and produces a nice
summary, sorted by mail folder:

-------------------------------------------------------------------------------
#!/bin/sh
# Summarize the ~/.procmaillog file

LOGFILE=${LOGFILE:=$HOME/.procmaillog}

echo "Subject: Procmail Summary"
echo " "

sort ${LOGFILE} | /usr/bin/awk '
/^  Folder:/ {
        folder = $2;
        nbytes = $3;
        msgcount[folder] += 1;
        totalbytes[folder] += nbytes;
}

END {
        for (folder in msgcount)
                printf "Folder %s:\tsaved %d messages (%d bytes)\n", \
                        folder, msgcount[folder], totalbytes[folder];
}
'

if [ "$1" = "-clear" ]; then rm -f $LOGFILE; fi
-------------------------------------------------------------------------------

To arrange to have it run daily, I use the following crontab entry:

0 7 * * * /Home/janzen/bin/pmsumm.sh -clear | elm -s "Procmail Summary" janzen

which means, "At 7:00AM every morning, run the pmsumm.sh script, use the
Elm mailer to mail the output to me, and then clear $HOME/.procmaillog".
See the "cron" man page for your system, and/or talk to your sysadmin,
since this varies among different flavors of Unix.


Hope this helps...

--
Martin Janzen           janzen@idacom.hp.com