At 00:39 -0400 on 07/05/2005, Valdis(_dot_)Kletnieks(_at_)vt(_dot_)edu wrote about Re:
IP::DOMAIN Associations [Re: Bounce/System Notification:
Mostly because *SOME* of us are concerned about *actually* getting mail
through, and we really have better things to do than to break our *own* user's
mail just because their MUA is accidentally configured to send with a From:
user(_at_)vt(_dot_)edu address, but to send to their ISP's mail server.
Unless your (ie: The VT.ETU) MSA Mail Servers do not listen on
Port587 but only Port25 or do support SMTP-over-SSL on Port465, there
is IMO no reason for their MUA to be pointing (accidentally or not)
at their current CONNECTIVITY ISP's MSA server. The only VALID (again
IMO) hypothetical reason to be using the CONNECTIVITY ISP's MSA
server instead of VT.EDU's MSA would be, as I stated, due to VT.EDU
not providing a Non-PORT25 MSA to accept email from CONNECTIVITY ISPs
that do Outgoing-Port25-blocking (or the user using an old MUA that
did not support designating what port to use for MSA upload
connections).