XADM: Store Hangs During Move Mailbox Process

When you perform a Move Mailbox procedure (or shortly after), the source or destination servers that are involved in the process may stop responding (hang). Clients that attempt to log on cannot finish logging on, and e-mail messages do not leave the Outbox for clients that are already logged on.

This issue can occur because the information store regularly checks to determine whether a specified user is involved in a move-user operation before the information store allows certain activities (such as message delivery, or logging on).

If no users are being moved, the check returns immediately with FALSE (this user is not being moved).

If users are being moved, the information store enters a critical section object and scans a list of users who are being moved to determine whether the specified user is on the list. After information store scans the list, the thread exits the critical section.

A specific condition exists, in which an information store thread enters a critical section, but does not exit the critical section before the information store thread returns from the function call. As a result, future threads that attempt to check the list of users that are being moved stop responding while the threads wait to enter the critical section object.

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: The following files are available for download from the Microsoft Download Center:
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.

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.