XADM: Mail May Be Lost During MoveUser Between Two Exchange Server 5.5 Computers by Means of Exchange 2000 Server

When you move a user from one Exchange Server 5.5 computer to another by means of a Microsoft Exchange 2000 server, mail sent during the move may be lost. You may not receive a non-delivery report (NDR) for the messages that are lost.

The logs indicate that the following steps occur automatically in a MoveUser operation:

1. A new mailbox for the moved user is created on the destination server.
2. A different thread in the information store delivers a message to the newly created mailbox.
3. The administrator tool sets the InTransit flag on the mailbox that was created in step 1.
4. All delivery threads deliver mail for this new mailbox in the InTransitFolder instead of the actual folder.
5. After the move is finished, the InTransit flag is removed, and the InTransitFolder is flushed to the new mailbox.
6. A message arriving at Step 2 is missing, as it is delivered after the mailbox is created, but before it is tagged as in transit.

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:

Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 4.