At 08:34 -0400 on 03/29/2007, John C Klensin wrote about Re:
RFC2821bis-01 Issue 3: EHLO parameter:
Do you see cases in the wild in which a client goes to the
trouble to do ESMTP AUTH and get it right and still can't manage
a correct domain name?
I can point out a case where this occurs. I use the Mac Version of
Eudora (at the 6.4.2 level as I document by my injected X-Mailer
Header) and it uses my LAN firewall IP Address (192.168.1.11) in its
EHLO not the DynDNS FQDN for my Connection (I run a private DNS
Server what has the DynDNS host name connected to my rDNS PTR record
so it is Accessible to but not used by the MUA).