I tried setting up Spamassassin with a couple of test local user_prefs.
I set allow_user_rules to 1 in local.cf
What i noticed was when a message was rejected, it could not be sent back to the sending user (prob because it already scored so high, that it gets scanned again, and then can't be sent out).
But even non-offending messages were not being delivered.
Does anyone have any ideas or has anyone done this?