Moving mailboxes in Exchange Server 2003

The move mailbox process in Exchange Server 2003 includes several improvements over the same Microsoft Exchange 2000 Server process. This article describes these improvements, offers suggestions for successful mailbox move procedures, and includes general troubleshooting information.

Moving Mailboxes by Using Exchange System Manager

To move mailboxes on Exchange 2000, you use the Move Mailbox command in Active Directory Users and Computers. On Exchange Server 2003, this command is also available in Exchange System Manager. When you use Exchange System Manager to move mailboxes, you can easily move all users from one database or server to another location. As the number of Exchange users in your organization fluctuates, you can move mailboxes to help adjust server workload.

Note Mailbox moves are supported on Microsoft Exchange Server 5.5 Service Pack 3 or later.

To move mailboxes on Exchange Server 2003, follow these steps:

1. Start Exchange System Manager on the Exchange Server 2003 computer where you want to run the process.
2. Double-click Servers, and then locate the server container where the mailboxes of the users are located.
   
   For example, if you want to move mailboxes from the default storage group and mailbox store, double-click First Storage Group, double-click Mailbox Store, and then click Mailboxes.
3. In the right-hand pane, click the mailboxes you want to move.
4. Right-click the selected users, and then click Exchange Tasks.
5. In the Exchange Task Wizard, click Next.
6. On the Available Tasks page, click Move Mailbox under Select a task to perform, and then click Next.
7. On the Move Mailbox page, click a destination in the Server list, and then click a mailbox store in the Mailbox Store list.
8. Click Next.
9. Configure how you want any corrupted messages that are found during the move to be handled, and then click Next.
10. Click Next.

Mailbox Move Processing In Exchange Server 2003

In Exchange Server 2003, you can run multiple mailbox moves at the same time. For example, you can start moving mailboxes on one database, and then start another mailbox move session from another database on the same server. The mailbox move process is now multi-threaded, and the processes run separately and at the same time. The number of moves that you can run at the same time depends on the hardware that you use and on the number of mailboxes that you want to move.

Note Four threads are used for each instance of Move Mailbox.

In Exchange Server 2003, you can also automatically skip and log corrupted mailbox items. In Exchange 2000, the whole move mailbox process would fail if a corrupted item was found. When you move mailboxes in Exchange Server 2003, you can stop processing the source mailbox if corrupted items are found or you can skip the corrupted items and continue the mailbox move.

Note The number of items that you can skip during a move is controlled by using the Maximum number of corrupted items to skip value. The default value is 3 and it can be set as high as 100; this value can be configured when you start the mailbox move process.

Because corrupted items are permanently deleted from the mailbox, you must back up the source mailboxes before you try to move mailboxes. For example, if you skip up to six corrupted items, you can delete up to six messages from a mailbox and still successfully move the mailbox. If the maximum number of corrupted items is exceeded, the mailbox is not moved.

When you move mailboxes in Exchange Server 2003, you can also specify an end time (or cut-off time) for the move process. For example, you can select a group of mailboxes to move overnight; the move operation is automatically canceled for any mailboxes that are not completely moved by the cut-off time that you configured. Any mailboxes that have not been completely moved are rolled back to their source location. Mailboxes that are moved before the cut-off time remain in their new location.
During the move, a detailed move mailbox report log is generated. This report is in XML format and is saved in the drive:\Documents and Settings\Profile\My Documents\Exchange Task Wizard Logs folder, where drive is the hard disk where Microsoft Windows is installed and where Profile is the profile folder for the user who initiated the mailbox move procedure.

Note The report can be opened automatically after the mailbox move is complete.

If a user tries to sign in to their mailbox while it is being moved, the following event will be logged in the Application log on the Exchange Server 2003 computer that hosts the mailbox:

Event Type: Warning
Event Source: MSExchangeIS
Event Category: Logons
Event ID: 9660
User: N/A
Description: User Username (FQDN of Username) failed to log on because their mailbox is in the process of being moved. For more information, click http://search.support.microsoft.com/search/?adv=1.

The Move Mailbox feature in Exchange Server 2003 helps to prevent the accidental movement of system mailboxes. If you try to move the System Attendant mailbox, you receive the following error message: If you try to move a Simple Mail Transfer Protocol (SMTP) mailbox, you receive the following error message: If you try to move a system mailbox, you receive the following error message:

Recommendations When You Use the Move Mailbox Feature

Microsoft recommends that you back up the source mailbox server before you try to move any mailboxes. Additionally, perform a full online Exchange backup of the destination server after the mailbox moves are complete. Also, consider backing up messages to .pst files; this will allow for quick recovery if individual mailboxes cannot be moved successfully.

For every gigabyte of data that you move, an additional gigabyte of transaction logs is generated at the source and target server. Verify that you have sufficient free space on your transaction log drives. If you do not have sufficient free space on your transaction log drive for transaction log file generation, you could temporarily turn on circular logging on the General tab of the storage group's properties page. If you have turned on circular logging during the mailbox move, make sure that you turn circular logging off when the mailbox move is completed. If you leave circular logging turned on, you cannot restore up to the point of failure if the database has to be restored from a backup. If disk space is a concern, you may also want to consider performing incremental backups during the mailbox moves to clear log files. For more information about how to move mailboxes in Exchange 2000 Server and in Exchange Server 5.5, click the following article number to view the article in the Microsoft Knowledge Base:

Event and Error Messages That Are Related to Mailbox Moves

If your organization includes a Microsoft Exchange Server 5.5 that is connected by using the Microsoft Active Directory Connector, stop replication over one or more recipient Connection Agreements until the mailbox moves are complete. After the changes have replicated throughout the Microsoft Active Directory directory service, restart replication.

How to Troubleshoot Mailbox Moves

If you experience problems during the move mailbox process, see the move mailbox log that is described earlier in this article.

You can also increase the level of detail that is captured in the Application log by increasing the logging level. To do this, follow these steps:

1. In Exchange System Manager, right-click the source server, and then click Properties.
2. Click Diagnostics Logging.
3. In the Services list, double-click MSExchangeIS, and then click System.
4. In the Categories list, click Move Mailbox.
5. Under Logging level, click Maximum, and then click OK.

Other issues that you may experience during the move mailbox process may include the following:

• Size limits on the destination server, including mailbox size limits, can prevent successful mailbox moves. Exchange Server 2003 Standard Edition includes a 16-gigabyte limit.
• A mailbox must be associated with a valid account. If the account that is associated with a mailbox is disabled, the associated external account must reference SELF in the Active Directory directory service or in a resource account.
  
  Note The SELF account is available in all Microsoft Windows 2000 domains. All SELF accounts share a well-known security identifier that is the same across all domains.
• View the Admindmp.txt file to troubleshoot issues that occur during or after a mailbox has been moved.
• Try comparing the mailbox attributes on the problem mailboxes with mailboxes that are known to be good to determine whether a configuration difference is causing the move issues.