. verification of reverse DNS¹
. helo verification¹
. strict sender/recipient verification²
. greylisting²
. content scan²
. delays
Also dynamic IP address filtering, and rather then using DROP or DENY, I have found DEFER does a very nice job in frustrating multi-attempt spammers.
--- DynaStop: Stopping one dynamic IP address at a time. Tested against 350+ million IP addresses!
http://tanaya.net/DynaStop/
pgpleY155gK7j.pgp
Description: PGP signature
-- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
