Chapter 4. SpamAssassin as a Learning System

SpamAssassin provides many rules that have proven useful in distinguishing spam from non-spam messages, and these rules are updated at each new release. But SpamAssassin provides more than just generic rules; it has the capability of learning about your email environment and adapting its detection behavior to maximize its accuracy in that environment.

SpamAssassin includes two adaptive systems that can be used in concert: autowhitelisting and Bayesian filtering. This chapter discusses the principles, configuration, and operation of both systems.