Julian Mehnle wrote:
However,
if the MTA(s) can use the domain name (example.org) instead of the MX name
(mx.example.org) in its HELO/EHLO commands, additional SPF records can be
saved without requiring additional lookups.
It's quite useful for debugging purposes to know the
one true name of the SMTP server. Consider the case
of a farm of servers sitting behind a BigIP load
balancer. To the outside world, it's a single IP, but
those who can see the one true name can tell which of
those servers is broken or mishandling their email.
I would not like to give that up to save a lookup.
Len