Fight The Spam! Redux

There was an excellent article recently about using statistical techniques to separate spam from real email. I linked to that article just a couple of weeks ago. This spam detection article builds on the first one and talks about some potential improvements to the algorithms mentioned. Bravo. I hope to see a lot of this built into software in the future.
Currently there is no good reason why we shouldn’t have a pluggable filtering system in products like Ximian Evolution and Microsoft Outlook Express. Their built-in filtering systems based on rules are inadequate and have proven themselves to be so for years now. Provide a simple way for someone to write a plug-in and then we can all take advantage of more sophisticated systems like these that examine the email for us and make decisions that are: a) likely to trap most of the spam, and b) aren’t likely to get false positives that cause email we really want to be tagged as spam.