Murray S. Kucherawy wrote:
From: owner-ietf-smtp(_at_)mail(_dot_)imc(_dot_)org [mailto:owner-ietf-
smtp(_at_)mail(_dot_)imc(_dot_)org] On Behalf Of J.D. Falk
Sent: Friday, March 26, 2010 8:50 AM
Subject: Re: New Version Notification for draft-macdonald-antispam-
Yup, me too. I'd also be curious how the most common MTAs (sendmail,
postfix, exchange, etc) react to reply codes they've never seen before.
They /should/ handle 'em gracefully, but there could be surprises.
I don't recall seeing any code in sendmail that reacts to other than the first
digit of the SMTP reply code itself, and nothing that looks at the enhanced
status code. No idea about other MTAs.
This might create a need though.
I don't think so.
The problem with this discussion is that we are dealing with a world
of mix bags of frameworks and individual input is based on what they
are used to.
The fact is, many of those response details come after the fact, after
te mail is receive where a post SMTP mail processor, i.e. a router
will either continue to router it for a remote destination, post it
for a local hosted user or bounce it.
While I feel there are a growth of integrated systems, at the SMTP
level most will not have these details to provide at the dynamic SMTP
session, Online, transport, whatever one wants to call it, level.
For example, the list expander at SMTP, that is one model of the
SMTP/LIST framework. The other may be a list server running separator
eyeball a queue of SMTP accepted mail. A failure here may end up
being a bounce.