Have you tried Spam Bayes
http://spambayes.sourceforge.net/
I used it for about a year and it's quite good and free. I am now using Bloomba in place of Outlook and I kind of like it even though I have the latest copy of Microsoft Office with the new Outlook sitting on a shelf.
Bloomba has a built-in version of Spam Assasin.
After tweaking my filters at the server level I am hardly getting any SPAM where before I would get dozens every day. Something FQuest should do is to try and implement some of the other SA options. On another host that I use I can for e.g. specifiy only English so I do not receive those horrid Chinese spams which I cannot even read anyway.