# (W) 2009 Alan W. Rateliff, II
#
# procmail recipe to automatically generate case numbers for emails
# received without subjects, and auto-reply with a subject reflecting
# the case number, and a message contained in ~/nosubject.txt
# detailing what has been done with the original message.
#
# The recipe rewrites the Subject line before delivering it
# locally, which is probably bad behavior, but no more than
# important emails with no subject.  This does not break signed
# messages since only the body is signed, not the headers.
#
# The case number is a simple checksum of the current time and date,
# which generates a nice and simple 10-digit number.  You can use
# other sources for the checksum, like the current PID or a random
# number, whatever you like.  But I recommend staying away from
# other algorithms; I thought of using CRC32 or MD5, but the
# numbers generated are far too unruly to be practical, especially
# if you wanted to modify this to assign case numbers to ALL
# emails instead of just those missing subjects.  Although, you
# could use awk to truncate the generated number.  Just a thought
# as you can ultimately do anything you desire.
#
# I am not sure if I should have used a lock file (:0:), but never
# the less, this recipe works, and works well.
#

:0
* !^FROM_DAEMON
* !^FROM_MAILER
* !^X-Loop: nosubject_reply
* ^Subject:([  ]$|$)
{
 :0 fw
 | CASE=`date "+%Y%m%d %k%M%S"|cksum|awk '{print $1}'`; \
   formail -A"X-Loop: nosubject_reply" \
    -t -i"Subject: Support case $CASE"

#
# I use a customized dmail on my system to deliver to mbx-formatted
# mailboxes contained within directories.  If you do not use dmail
# on your system, change the action below to
# $DEFAULT
#
 :0 cw
 | /usr/local/bin/dmail -q

 :0 hw
 | (formail -rtk -A"Precedence: junk (autoreply)" 
    -A"From: \"-your full name-\" <your@email.add>"; \
   cat $HOME/nosubject.txt) | $SENDMAIL -t
}