This plugin implements the threshold-based auto-learning discriminator
for SpamAssassins Bayes subsystem. Auto-learning is a mechanism
whereby high-scoring mails (or low-scoring mails, for non-spam) are fed
into its learning systems without user intervention, during scanning.
Note that certain tests are ignored when determining whether a message
should be trained upon:
* rules with tflags set to learn (the Bayesian rules)
* rules with tflags set to userconf (user configuration)
* rules with tflags set to noautolearn
Also note that auto-learning occurs using scores from either scoreset 0
or 1, depending on what scoreset is used during message check. It is
likely that the message check and auto-learn scores will be different.
The score threshold above which a mail has to score, to be fed into
SpamAssassins learning systems automatically as a spam message.
Note: SpamAssassin requires at least 3 points from the header, and 3
points from the body to auto-learn as spam. Therefore, the minimum
working value for this option is 6.