SPAM Bounce

[Matt]

I am/was currently bouncing SPAM by using blacklists in sendmail.cf.  This
had the benefit of letting the sender know that the message did not go
though and used minimal resources.  If it bounceded a legitiment message the
sender would know rather then quietly deleting it.  No one liked the SPAM
tagging I tried in the past either.  I used Spamcop, Ordb and the proxy list
at monkeys.  The real problem with it was that if one of my users wanted it
turned off for there account there was no way to do that.  So I bravely
upgraded my Raq4i from MS 3.x to 4.x last night.  Set it up to bounce SPAM
based on the same blacklists and let it go(hours later, ugh).  Now my admin
account filled up with messages from "Mail Delivery Subsystem" due to the
undeliverable messages and it also seems that my queues flooded full to.  I
am no linux/sendmail whatever expert so was not real sure what all was going
on.

Anyway, is anyone out there using the SPAM "bounce" option with success?

Matt