On Mon, 24 Jan 2005 22:29:49 +0100, Markus Stumpf <maex-lists-nanog@space.net> wrote:
If you look at your logfiles you will notice that > 95% of all legit mailservers already have working and individual revDNS.
About the rest of the post - others have commented on MTAMARK .. I'll just point out that you are generalizing based on a case you see in your mailserver I havent got the time to gather stats from our production clusters right now but a quick grep through the last week's logs on my personal colo (lots of ISPs in india mail it, some indian users - friends, family, large local linux lists - on it) .. I'd say that about 40% of my legitimate email comes from IPs that don't have rDNS let alone DNAME / MTAMARK. On our production boxes we get email from around the world for about 40 million users, and I just dont want to try blocking based on no reverse DNS there .. just not worth the amount of legitimate email traffic that gets filtered out. -- Suresh Ramasubramanian (ops.lists@gmail.com)