On 2010-01-21 05:17 +800, Email Archive wrote:
> For me greylisting all mail eliminates most of my spam and I hardly ever
> receive any calls regarding it.
Greylisting is indeed very effective at filtering out bot-sent spam,
which account for more than 80% of global spam now. You can also couple
it with auto whitelist to reduce transimission delay caused by greylisting.
Whenever your users send e-mail, the recepients are very likely to reply.
So why not let their reply bypass greylisting (with exim ACL) automatically?
Please refer to the following posts for some implementation idea of auto
whitelist for exim:
http://www.gossamer-threads.com/lists/exim/users/68306#68306
http://www.gossamer-threads.com/lists/exim/users/68924#68924
Chih-Cherng Chin
Botnet Detection with Greylisting:
http://botnet-tracker.blogspot.com/2009/11/greylisting-botnet-detection-honeypot.html