Editing Apache SpamAssassin (section)

==Bayesian filtering==
Apache SpamAssassin reinforces its rules through [[Bayesian spam filtering|Bayesian filtering]] where a user or administrator "feeds" examples of good (ham) and bad (spam) into the filter in order to learn the difference between the two. For this purpose, Apache SpamAssassin provides the command-line tool {{mono|sa-learn}}, which can be instructed to learn a single mail or an entire mailbox as either ham or spam.

Typically, the user will move unrecognized spam to a separate folder, and then run {{mono|sa-learn}} on the folder of non-spam and on the folder of spam separately. Alternatively, if the mail user agent supports it, {{mono|sa-learn}} can be called for individual emails. Regardless of the method used to perform the learning, SpamAssassin's Bayesian test will help score future e-mails based on this learning to improve the accuracy.