Autor: Always Learning Data: A: Exim Users Assumpte: Re: [exim] Rejecting messages with no "To:" or "Cc:" field in
theheaders
Bill Hacker wrote .........
> "Real folks" MTA have DNS creds. Botnet WinZombies do not. QED.
The facts of everyday email receiving is some very large organisations
give out false HELO / EHLO and/or have non-resolving hosts.
Perhaps it really is time for a SMTP RFC stating that:
(1) HELO / EHLO must resolve to the IP address of the sending server;
(2) The sending server (MTA) must have a resolving host name.
Exim provides excellent tools for rejecting spam but when large
organisations, some operating internationally, can not care less the
dilemma for others is whether to adhere to one's own standards or
succumb to accepting spam, virus and Trojans into the system.
I reject virtually everything not 100% correct. It produces a (so far)
100% spam free operation. A selection of other people's standards can
be seen on sys.u226.com/t21/t21.php