Purposely bouncing selected mail?

[karl_kleinpaste at charcoal.com]

jlol at remus.ee.byu.edu writes:
   Let's suppose I'm on some junk mail mailing list that I haven't been
   able to get off of.  How can I make mail from that particular
   person/list bounce or appear (convincingly) to have bounced without
   having to change my email address?

The following suggestion is entirely untested, but the principle
should be reasonably obvious.

In .forward, place this:
	\jlol, "|/home/dirs/jlol/bin/bouncer"

Then the bouncer script could look like...

    ----------------
#!/bin/csh -f
#
# Bouncer: a script to scan incoming mail to see if it comes
# from the "wrong" place, and fakes a bounce-o-gram back if so.
#
set t1=/tmp/bounce.a$$
set t2=/tmp/bounce.b$$
#
# Save the mail; then pull out the From_ address.
cat > $t1
set origin="`head -1 $t1 | awk '{ print $2 }'`"
#
# If it comes from the wrong place (hopefully, a *-request@* form)...
if ("$origin" == bad at addr.ess) then
	#
	# Bad juju.  Preformat a pseudobounce-o-gram.
	cat << EoF > $t2
To: $origin
Subject: Returned mail: User unknown
From: mailer-daemon at remus.ee.byu.edu

   ----- Transcript of session follows -----
   554 jlol...User unknown

EoF
	#
	# Stuff it directly into sendmail.
	(cat $t2 ; tail +2 $t1) | /usr/lib/sendmail -t
endif
#
# Clean up.
rm -f $t1 $t2
exit 0
    ----------------

Embellish to taste.

--karl