Be aware that corrupted data items that the wizard deletes before reaching the threshold are permanently deleted and aren't recoverable. Consequently, if you don't back up the source database before you start the move mailbox operation, you won't be able to recover corrupted items that the wizard encounters and deletes.
If you don't want to tolerate any problem items during the move operation, you can have processing of that mailbox terminate immediately by selecting a corrupted-items threshold of 0. Then, when the Move Mailbox Wizard encounters a corrupt item, the wizard will move on to process the next mailbox. Because a corrupted item usually means that the Exchange database is corrupted, running the Eseutil utility might resolve the problem.
Status Updates and Reporting
After a mailbox move session is finished, the Move Mailbox Wizard will produce a detailed XML report of the move. The wizard will display information about pending moves, moves currently in progress, failed moves, and completed moves. The report also displays the amount of time remaining before a scheduled move operation will begin and elapsed times for moves. You can analyze the report offline or incorporate it into other reporting or administrative systems. To manipulate the report's data, you can simply use a custom XML style sheet.
A Better Tool
The Exchange 2003 Move Mailbox Wizard's multithreading and scheduling capabilities are much improved over earlier versions. The new wizard is a valuable tool for moving users from Exchange 2000 servers to Exchange 2003 servers and is indispensable for moving users off Exchange 5.5 servers.
However, if you need to move mailboxes between Exchange 5.5 sites while in mixed mode or perform interorganizational mailbox moves, you need to consider another approach. In these situations, you can use the Mailbox Merge Wizard, the Exchange Migration Wizard, or a third-party tool to accomplish the necessary moves.