I've just signed up for Marc Perkel's spam filtering service because I'm sick of managing the spam arms race. It's a near full-time job and my Linode just doesn't have the RAM to do it. I mean, the latest method is to OCR, then filter these image spams!
So now I've moved over to this service and we'll see how it goes. He needs better documentation of the setup, so I might just write some stuff for him, in exchange for some free months or summat.
Now waiting for the MX records to expire on some of the places I get mail from, then it should start all going through his servers. From there I should be able to block access to my mail server from everywhere except his. Most importantly, I can turn off all my own spam filtering and get my life back.