Bogofilter's a mail filter that classifies e-mail as spam or ham (non-spam) by a statistical analysis of the message's header and content (body). The program's able to learn from the user's classifications and corrections. It was originally written by Eric S. Raymond, and's now maintained together with a group of contributors by David Relson, Matthias Andree and Greg Louis. The statistical technique used's known as Bayesian filtering and its use for spam was first described by researchers at Mic… (More on Bogofilter)