...which is why their spam filters are so much more effective than bayesian filtering -- which is the only tool you have if you 'go it alone' on email This is

...which is why their spam filters are so much more effective than bayesian filtering -- which is the only tool you have if you 'go it alone' on email This is not true at all. Of the top of my head, I can think of three different distributed message hashing services (Razor, Pyzor, and DCC) that function similar to a shared Bayesian filter, not to mention all the various IP and URI blacklists that collect and share data about bad actors. I've actually done mail server installs where I've turned off the local bayes filters to improve results because they were getting confused by low volumes. SpamAssassin comes with just about every Linux distribution and is used by major ISPs, so you're not "going it alone," you're leveraging what a huge percentage of the internet population is already using. It's not without effort (maybe 15-30 minutes/week of tweaking when something slips through), but my personal email setup gives me as good or better results than my infrequently-used Gmail account.