Just so I understand you clearly, you think that Spam Assassin is "not" the problem? :-) haha
This weekend I was asked to redirect one of the three mail accounts on this server to a different email service. I was thinking of disabling Spam Assassin (since it's one of the top three memory hogs) but based upon your note, that's probably not necessary... ?
(Thanks for the perl tip. I just haven't had time to look yet, but I'll try to install Sirdude's suggestion tonight.)
