this happens after users mailbox moved from one exchange to other (in one organization, but differend domains)
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.