I like to have a procmail logfile to find possible bugs in my ~1000 lines of mail filter rules. But if you get around thousand mails a day, the logfile size becomes bigger and bigger. And I always forget to remove that logfile. So I decided to let procmail do that job. I want to have a logfile structure logs/procmail/$YEAR/$MONTH/$DAY.log and I want the logfiles to be compressed daily and I want them to be kept for one month. This is how it looks like:

PATH="/bin:/usr/bin:/usr/local/bin:/usr/sbin:$HOME/bin"
MONTH=`date +%m`
YEAR=`date +%Y`
DAY=`date +%d`
YESTERDAY=`echo $DAY-1|bc -l`
LAST_MONTH=`echo $MONTH-1|bc -l
LAST_MONTH=`test $LAST_MONTH -eq 0 && echo 12 || echo $LAST_MONTH`
RM_RESULT=`test -d "$HOME/log/procmail/$YEAR/$LAST_MONTH" && rm -rf "$HOME/log/procmail/$YEAR/$LAST_MONTH"`
MKDIR_RESULT=`mkdir -p $HOME/log/procmail/$YEAR/$MONTH`
BZIP_RESULT=`test -f "$HOME/log/procmail/$YEAR/$MONTH/$YESTERDAY.log" && bzip2 "$HOME/log/procmail/$YEAR/$MONTH/$YESTERDAY.log"`
LOGFILE="$HOME/log/procmail/$YEAR/$MONTH/$DAY.log"

Yes, I know, I could do this in a cron. But it was funny to do it in the procmailrc.

Ein Problem von procmail ist die unstrikte Syntax. Wenn man aus Versehen bösartige Direktiven in der .procmailrc platziert, so landen die Mails alle in einer großen Datei, die keine MBox ist. Ein Beispiel:

:0

br />^X-BeenThere: list@youfavouritehost\.com$

.Path.To.Your.Imap.Box/

#! /usr/bin/ruby

a = 0

File.new( “heap_of_mails” ).read.split( /\n\nReceived: / ).each |m| {

    a = a.next

    File.new( “outputdir/” + a + “_mail.txt”, File::CREAT|File::TRUNC|File::RDWR, 0640 ).write( “Received: “ + m )

}

for file in outputdir/_mail.txt ; do cat $file | procmail ; done