sendmail+procmail+cyrus, return-path, sieve

[Will Partain]

This scenario, and ones like it, has been discussed here
before.  I've got something working, so am posting details
{in case it's useful, so you can tell me I'm an idiot:-)}.

The 'vacation' bit of sieve wasn't working, because it kept
seeing a useless 'deliver'-created Return-Path: header.

I was starting procmail from sendmail, with a procmail
recipe something like this:

   # *OLD*
   CYUSER=$1

   # Run spamassassin:
   :0fw
   | /our/bin/spamassassin -x -p /etc/mail/spamassassin.config

   # All the mail that falls through to this point
   # will be delivered into the user's INBOX 
   :0w:$CYUSER.lock
   | $DELIVER -a $CYUSER $CYUSER

   # If that fails, report back whatever $DELIVER said:
   EXITCODE=$?
   :0
   /dev/null
   # end *OLD*

This worked fine, except for sieve vacation.  Why?
'deliver' would run and insist on tossing in a "Return-Path:
cyrus at foo.verilab.com", even though there was a perfectly
good Return-Path: already in the message.  (Result: two
Return-Path:s) Of course, then sieve would send all vacation
messages to 'cyrus at foo.verilab.com', who didn't appreciate
them.

I couldn't see a way 'round it except to fish out the
pre-existing Return-Path: and force 'deliver's hand (with
-r).  So I now have:

   # *NEW*
   CYUSER=$1

   # snag the existing Return-Path:
   RPTMP=`/usr/bin/formail -xReturn-Path: | /bin/sed -e 's/^ *<//' -e 's/>$//'`
   RETPATH=${RPTMP:-badbadbad}

   # Run spamassassin:
   :0fw
   | /our/bin/spamassassin -P -x -F 0 -p /etc/mail/spamassassin.config

   # All the mail that falls through to this point
   # will be delivered into the user's INBOX 
   :0w:$CYUSER.lock
   * ! RETPATH ?? badbadbad
   | $DELIVER -a $CYUSER -r "$RETPATH" $CYUSER

   # if we get here, something bad happened re the Return-Path:
   :0w:$CYUSER.lock
   | $DELIVER -a $CYUSER $CYUSER

   # If that fails, report back whatever $DELIVER said:
   EXITCODE=$?
   :0
   /dev/null
   # end *NEW*

As best I can tell, this is vacation'ing happily.  I would
be grateful for any improvements that you may suggest.
Regards,

Will