On Thu, 12 Nov 1998 03:13:53 +0300 Alexey Melnikov
<mel(_at_)taxxi(_dot_)com> wrote:
I am sorry for not being precise. I mean *server implementations* (I am
not interested how to configure clients, I want to know if there is any
server (MTA-to-MTA) [de-facto] standard)
Short answer: No
There are also multiple reasons why this would be a bad idea.
They include reintroducing a reason for explicit source routes
and a great deal of confusion if the target domain actually
labels a set of MX records for hosts that don't all use the same
port. If this is "first hop" (e.g., "message submission"), then
the comments others have made about configuring clients probably
apply. If it is trying to reach a general far-end system on a
peculiar port, it probably can't be made to work in the general
case: the port data would really have to be in the DNS somehow,
and running standards/well-known services on variant ports is
usually considered offensive to both the architecture and even
elementary security considerations.
john