On Sun, Jul 17, 2011 at 09:07:38PM -0500, Les Mikesell wrote:
There is no requirement for the greeting name to match any IP, and isn't likely
RFC2821 says: - The domain name given in the EHLO command MUST BE either a primary host name (a domain name that resolves to an A RR) or, if the host has no name, an address literal as described in section 4.1.1.1.
So, pretty much, HELO or EHLO greeting _must_ match to an IP.
(RFC821 actually wanted the HELO to match the connecting host, but 2821 just says it must be an A record or an address literal).