Related to my post here on SO:
https://stackoverflow.com/questions/3638584/smtpclient-sending-bad-messageids/3638682#3638682
It was brought to my attention that our exchange settings may be incorrect.
Overview
The messages sent by the emailer (SMTP) have incorrect MessageID headers.
Message-ID: <98bcd4e6-be30-4b22-8026-6047c8231b1f>
Where they should look something like this:
Message-ID: <F09A215A213060419E28A88E85FDC8FD0CCEB91C23@EXCHANGE-SERVER.MYDOMAIN.mycompany.com>
I'm assuming one of our settings are incorrect, anyone know what needs to change?
Pierre 303 is incorrect about who is responsible for setting the Message-ID header. SMTP requires that there is one, it does not specify who creates it. Mailers are supposed to provide one if an incoming message lacks one, which does not stop programs that send mail from setting their own.
As it happens, Exchange 2007 SP1 does have an issue related to this (link). If you happen to be running before this version this might be why the Message-ID is not being completely filled out per conventional usage.