this happens after users mailbox moved from one exchange to other (in one organization, but differend domains)
details:
From: postmaster Sent: Saturday, April 03, 2010 8:43 AM To: USER1 Subject: Undeliverable: subject of message
Delivery has failed to these recipients or distribution lists:
IMCEAex-_O=DOMAIN_OU=First+20Administrative+20Group_cn=Recipients_cn=USER1@domain A problem occurred during the delivery of this message. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message later, or provide the following diagnostic text to your system administrator.
You can't get too far with troubleshooting this with just the non delivery report you posted above. There are two things you should do. First, get into Exchange System Manager and use the Message Tracking feature to track the message. Often it doesn't tell you much other than that it generated an NDR but sometimes there are clues (for instance, did the user's mailbox server generate the NDR or did it get forwarded to another server that then generated the NDR). Second, you need to look in the Application log of the server that generated the NDR for any associated errors. If you don't find anything, you should turn up diagnostic logging on that server for Transport to Maximum and send a few messages. You'll certainly get a few applicable errors in the Application log at that point and you'll then have something more useful to look at for troubleshooting purposes (including potentially posting an update here with the specific error).