On Wed, 6 Jul 2005 willemien(_at_)amidatrust(_dot_)com wrote:
If an MSA host accepts messages on port 25 then DNS-MX records SHOULD
NOT point to this host.
This rule isn't necessary. SMTP server software can distinguish between
MSA mode and MX mode using the fact that the client did or did not
authenticate itself. The only caveat is that systems that work like this
have less scope for pre-authentication anti-spam techniques because some
of these tricks can disrupt MSA clients in unpleasant ways.
Tony.
--
f.a.n.finch <dot(_at_)dotat(_dot_)at> http://dotat.at/
BISCAY: WEST 5 OR 6 BECOMING VARIABLE 3 OR 4. SHOWERS AT FIRST. MODERATE OR
GOOD.