XCON: MTA Drops Message and Fails to Send NDR During Move User Operation

During the move of a mailbox from one Exchange Server computer to another, messages may not be delivered to the primary recipient and no non-delivery report (NDR) is sent to the message originator. This behavior occurs when the following conditions exist:

• The user whose mailbox is moved has an alternate recipient.
• The deliver option to send to both the alternate recipient and the primary is selected.
• The delivery attempt occurs during the actual move user operation.

The message is delivered to the alternate recipient, but deferred to the primary recipient. At the end of the move operation, another attempt is made to deliver the mail. When the delivery fails because the correct user address is not in the message transfer agent (MTA) cache, no NDR is generated. With the fixed version of MTA, an NDR is generated and delivered to the message originator.

To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

As a workaround, you can remove the alternate recipient before you move a mailbox, and after the move, re-assign the alternate recipient.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Exchange Server 5.5 Service Pack 4.

For additional information regarding delivery issues during a move user operation, click the article number below to view the article in the Microsoft Knowledge Base: