Your search for "spam" returned 9 results:
RHSBL Support
Add support for filtering based on RHSBL-type blacklists in ORF, such as rhsbl.ahbl.org.
4 comments
21
Challenge / Response (C/R) Spam Filtering
A feature to send a reply email automatically with a challenge to unknown senders. The sender is asked to perform some action to assure delivery of the original message, which would otherwise not be delivered. Senders that have previously performed the challenging action would be automatically whitelisted.
25
Bayesian (or Other Statistical) Filtering
Add a new statistical filter test to ORF. The most widely known and used statistical technique is Bayesian filtering, a "learning" email classification method. When properly trained and maintained, statistical filters work very effectively.
However, they require a reliable feed of actual legitimate and spam messages for initial training, so end-users are likely required to participate in the training.
2
DONE Directory Harvest Attack (DHA) Protection
Add a new test to ORF that would temporarily reject all delivery attempts if the sending IP address is sending to more than "X" (user-configurable) non-existent recipients within in a specified period of time. This would provide some protection against poorly distributed or non-distributed Directory Harvest Attacks.