We recently acquired another company with their own Exchange server. We have setup mail accounts on our server with our domain name but the users also have their old mail addresses handy. What is happening is when someone sends an email to their new accounts from inside our organization, the mail goes through. When they send an email to the users old mail address (and their Exchange server is still up and running BTW) the message bounces back as below...
Delivery has failed to these recipients or distribution lists:
The recipient's e-mail address was not found in the recipient's e-mail system. Microsoft Exchange will not try to redeliver this message for you. Please check the e-mail address and try resending this message, or provide the following diagnostic text to your system administrator.
Sent by Microsoft Exchange Server 2007
Diagnostic information for administrators:
Generating server: AISHQEXC01V.aiscorp.local
#550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##
Original message headers:
Received: from AISHQEXC01V.aiscorp.local ([10.1.2.31]) by aishqexc01v
([10.1.2.31]) with mapi; Wed, 16 Jan 2013 13:08:58 -0500
Content-Type: application/ms-tnef; name="winmail.dat"
From: Stephan Laurie <SLaurie@aiscorp.com>
To: Friedrich Nolting <firstname.lastname@example.org>
CC: Friedrich Nolting
Date: Wed, 16 Jan 2013 13:08:57 -0500
I have also clicked on the To: field in Outlook, and the user is showing up with the old domain mail address. The really weird thing I can think of that is causing this is that the person in question was put in to Exchange as a contact at one point in time.