It seems as though that a previous administrator may have had some work done to our Exchange 2003 server to prevent users from being able to send email to certain recipients ( which are listed as contacts in AD) w/o authorization. We assumed that it was checking the contact for this certain external recipient that we had setup before sending the message. To try and get around the issue we simply deleted the contact. When using OWA messages seem to be getting delivered now. When trying to use outlook in cached mode, we seem to still be having a problem but different. When the messages is sent to their email address (externaluser@theirdomain.
com) we get a NDR that was the message could not be delivered to (firstname.lastname@example.org
m). Its flipping their domain for ours and it generates the NDR because we don't host a mail box for that user account here and its trying out email server is trying to deliver it locally. I can't think of any reason why this change the destination domain at all.
Also if there was any custom changes that were made when we were on Exchange 2003, we have since moved to 2007. We ran into some bumps in the road with our migration because we ran into some "custom" fixes such as this.
It also looks like it is trying to refer to a OU and CN that do not exists anywhere in our AD environment. It looks like it may have been a configuration that existed some time ago, but nothing that is current.
Diagnostic information for administrators:
Generating server: MAIL.company.local
#550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##
Original message headers:
Received: from MAIL.company.local ([192.168.1.8]) by MAIL.company.local
([192.168.1.8]) with mapi; Mon, 6 Jul 2009 10:55:20 -0400
Content-Type: application/ms-tnef; name="winmail.dat"
From: "user" <email@example.com>
To: "External User"
Date: Mon, 6 Jul 2009 10:55:18 -0400