Antispam Configuration
Apache James Server Anti-Spam system can be configured via two main different mechanisms:
AntiSpam SMTP Hooks
"FastFail" SMTP Hooks acts to reject before spooling
on the SMTP level. SpamAssasin hook can be used as a fastfail hook, therefore
SpamAssassin must run as a server on the same machine as the Apache James Server.
SMTP Hooks for non-existent users, DSN filter, domains with invalid MX record,
can also be configured.
AntiSpam Mailets
- Black listing Mailet
- Grey listing Mailet
- SpamAssassin Mailet is designed to classify the messages as spam or not
with an configurable score threshold. Usually a message will only be
considered as spam if it matches multiple criteria; matching just a single test
will not usually be enough to reach the threshold.
- BayesianAnalysis in the Mailet uses Bayesian probability to classify mail as
spam or not spam. It relies on the training data coming from the users’ judgment.
Users need to manually judge as spam and send to spam@thisdomain.com, oppositely,
if not spam they then send to not.spam@thisdomain.com. BayesianAnalysisfeeder learns
from this training dataset, and build predictive models based on Bayesian probability.
There will be a certain table for maintaining the frequency of Corpus for keywords
in the database. Every 10 mins a thread in the BayesianAnalysis will check and update
the table. Also, the correct approach is to send the original spam or non-spam
as an attachment to another message sent to the feeder in order to avoid bias from the
current sender's email header.
