Bill? Spam Assassin was running at 72 megs? It is not not not the root of the problem, but nonetheless it caught my eye as that's too much. Is it up to date? Is the bayes_seen really really large? 72 megs and (likely) a whole lot of CPU is just too high for Spam Assassin.
(by the way, if you have Spam Assassin installed then you have perl installed)