Greetings All, Inspired by an email from Richard Downing, I decided to look into using greylisting to help fight spam. If you haven't heard of it before see: http://www.greylisting.org
The basic idea is that whenever a new MTA (one that is not in the greylisting database) attempts to deliver mail, the mail is automatically rejected. If the MTA is a valid MTA, it will retry to deliver the mail after a few minutes. At this point the greylisting server recognizes the MTA from a previous attempt and assumes that it is valid mail. The address of the sending MTA is added to the database and future messages from that server are automatically allowed (at least for a while). I tried a Postfix implementation called Postgrey on my own personal server and the results were very good. (See http://postgrey.schweikert.ch/). Based on those results it was decided to implement this service on Quantum. Quantum already had SpamAssassin installed and it uses some nice Postfix reject rules to keep a good deal of spam at bay. Combine that with the fact that the mailing lists require a valid subscription to post and the result is that most spam never reaches the end users. Even so, a good deal of spam gets past SpamAssassin and Postfix and hits Mailman. And therein lies the problem we wish to avoid. Even though mailman rejects the message, the processing time mailman spends is expensive. Our hope is to eliminate a good deal of spam before it even 'enters' the system, so to speak. Be advised that your first post to a mailing list might be delayed by a few minutes. If it takes a considerably long time, or if you receive an undeliverable message from your MTA, please let us know at server-admin AT linuxfromscratch DOT org so that we can adjust our whitelisting files. If you have a linuxfromscratch.org mail account and you would rather not have greylisting applied to your personal mail at all, please send a message to server-admin and we can add your account to the whitelisting rules as well. -- JH -- http://linuxfromscratch.org/mailman/listinfo/blfs-dev FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
