I'm using postfix + spamassassin (amavis) now and I'm trying to increase my hit rate, so I've been looking at the logs to try to see any patterns in email that is obvious spam but gets low scores.
One thing I've noticed is I'll get a series of emails from the same sender to email accounts on my domain. If any of the recipients are to specific very old, closed accounts then the series of emails is almost certainly spam (but not all of my closed email accounts are good for this).
So what I'd like to do is create a auto-generated black-list (that I can edit) or spamassassin rule for senders who send to these specific email addresses. I know it wouldn't stop everything, but once they hit the tripwire email accounts they would be stopped.
Does anyone know of something that already exists that does this (I've looked, but maybe not with the right search terms), or can point me in the right direction as far as building a solution myself?
