Re: [Fwd: I-D ACTION:draft-klensin-rfc2821bis-01.txt]2007-03-26 02:42:00
Hector Santos writes:
Case in point, The Thunderbird MUA violates the EHLO [literal] when the client is residing on a private address behind a NAT. TBird attempts to get the FQDN and if not available, it uses the domain literal for the client machine. If a server is checking for strict IP correctness, it might fail this transaction.
I was blacklisted last week for doing the opposite - figuring out the correct IP address used and using the DNS name corresponding to that (dhcp-3424234.aconferencedomain.org). Seems ten million botnet members do that at the moment.
So perhaps a long-lived document like 2821bis had better not speak too much or too loudly on this subject. Whatever it were to say might just be obsolete in two years. The mail system is long-lived and changes slowly, each spam filter is short-lived and quickly replaced.