At this point I consider myself a competent SA admin. I've got one particular box with a domain going back to at least 1998 that I can't block enough spam, too

At this point I consider myself a competent SA admin. I've got one particular box with a domain going back to at least 1998 that I can't block enough spam, too much still gets through. SpamAssassin is great, but I've been using GMail since the beta and spam almost never gets through, like single digits for me in all that time.