Honestly, it may seem a bit presumptuous, but most of us are probably on unix mail servers. It also seems obvious that most of us probably use procmail.
That being the case, might I suggest using Spambouncer? http://www.spambouncer.org. Just add /path/to/spambouncer/folder/sb.rc to your list of recipes, and turn on the switches you want and you're set. I don't get spam. Period. Just a thought anyway. :)
