On Fri, Jan 04, 2008 at 07:51:15AM -0800, Seth Mattinen wrote:
Our mail servers reject connections that don't follow the RFC. Am I wrong to do this?
Nope. His software is either misconfigured or broken. I'm aware of the be-liberal-in-what-you-accept philosophy (and followed it for many years, still do in some cases), but no longer think it's applicable to inbound SMTP. The way I've put it is that the more someone's SMTP sender looks like a spam source -- say, missing rDNS or HELOing as something invalid or not sending valid SMTP commands -- the more likely it is that someone's mail system will reject, defer or quarantine the traffic. So it's in everyone's interest to make sure their outbound SMTP traffic is as compliant with de jure and de facto requirements as they possibly can -- doubly so given that this is quite often something as simple as fixing a HELO string or creating a single PTR record or something similar. ---Rsk