Mail.app’s Junk filter is not a Bayesian one like the spam catching technology in SpamSieve and many other spam-fighting apps. Instead it uses a technique called Latent Semantic Analysis (LSA).

I’ve blogged two excellent descriptions of the way this filter works in Apple Mail before, but today came across a third explanation with the imposing title, “Bayesian Nets, Latent Semantics, Despamming and other speculations”.

The post describes the differences between Bayesian and LSA and a whole lot more. It’s over two years old, but a good read and packed full of links to other resources on spam.

[via Paul's Time Sink.]