This article was previously published under Q328810
This article describes tips about how to move mailboxes between servers.
Moving mailboxes between servers in the same site can have disastrous consequences, including loss of data. This article is intended to help you avoid problems in moving mailboxes.
To help guarantee a successful move, consider the following steps:
Use ExMerge.exe to create a .pst file for each of the mailboxes that you plan to move. This gives you a recovery solution, in case you require one.
Plan to move mailboxes in manageable groups of 20 to 30 recipients at a time. Move mailboxes during a period of low activity. Inform the affected users so that they can log off before the move, if you want them to. You do not have to make sure that users have logged out of their mailbox before the move, because users are automatically disconnected during the move. Similarly, you do not have to limit logons to the mailbox during the move, because logons are limited automatically by the information store.
Note Although it is not a requirement, it may be preferable in some organizations to limit logging on to the Information Store before the mailbox move, as an added safeguard. For more information about how to prevent users from logging on to an Exchange 5.5 server, click the following article number to view the article in the Microsoft Knowledge Base:
To prevent logons to an Exchange 2000 server, a setting can be made to restrict logons from a MAPI client. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
328240 How to put server-side restrictions on clients that are used to access Exchange 2000 mailboxes
This restriction would not apply to Outlook Web Access (OWA), POP3, or IMAP4 clients. To restrict OWA, POP3, and IMAP4 clients, these protocols would need to be disabled. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
Temporarily disable your Exchange-aware antivirus program. There are some issues with the antivirus API that cause failure. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
271547 Move Mailbox utility does not work when antivirus API is in use
For every gigabyte of data that you move, an additional gigabyte of transaction logs is used. Therefore, verify that you have sufficient free space on your transaction log drive. If you do not have sufficient free space on your transaction log drive, 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 your database has to be restored from a backup. If disk space is a concern, you may want to perform incremental backups during the mailbox move to purge log files.
If you have problems, do not move the mailbox back to the original server. If you do so, you are likely to lose data. Instead, follow the steps in the following Microsoft Knowledge Base article:
252869 How to prevent mail loss when Move Mailbox operation is unsuccessful
Before a mailbox move from an Exchange 5.5 Source Server, perform a DS/IS consistency check on the private information store . To perform the DS/IS consistency check, click the Advanced tab of the server's properties page. For the Operation, click Private Information Store.
Important Select only the Remove unknown user accounts from mailbox permissions option. Select the box at the bottom to filter all inconsistencies.
It may be a good idea to run an offline defragmentation of your private information store on the source server after mailboxes have been moved. This reduces the physical size of the Priv.edb file. Backup and restore times will be reduced, and more disk free space will be available. This step is not necessary if you plan to decommission the source server and remove it from your Exchange site or Administrative Group.
If mailboxes are being moved from an Exchange 5.5 server to an Exchange 2000 server, we recommend that the Recipient Connection Agreement replication schedule be set to Never during the mailbox move. This helps you avoid any issues with the homeMDB attribute being reset to that of the Exchange 5.5 server. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
299473 The homeMDB attribute is reset after you move mailboxes from Exchange Server 5.5 to Exchange 2000 or to Exchange 2003
Move all the mailboxes to the new Exchange 2000 computer by using Active Directory Users and Computers. You must do this from the Exchange 2000 computer or from any computer with the Active Directory Users and Computers MMC Snap-in installed (such as a domain controller), and Exchange System Manager (ESM) installed. To move the mailboxes:
Click the Organizational Unit (OU), and then click User to select a single user. Or, to select multiple users at the same time, press the SHIFT or CTRL key.
Right-click the object or objects, click Exchange Tasks, click Move Mailbox and then click Next. Follow the instructions on the screen to move the mailboxes to the appropriate Exchange 2000 Server and Mailbox Store.
All users must log on to their mailboxes to automatically update their exchange profiles to point to the new Exchange 2000 server. If you remove the Exchange Server computer before the users update their exchange profiles, you must visit each user desktop to manually update their exchange profile to point to the new Exchange 2000 server.
251533 Moving mailboxes between Exchange Server 5.5 and Exchange 2000 Server results in store error c1040af4
247173 Cannot move a mailbox from an Exchange Server 5.5 computer to an Exchange 2000 Server or an Exchange Server 2003 computer
264413 Error connecting to destination server during Move Mailbox