Moving a computer that is running Exchange 2000 Server or Exchange Server 2003 to a different domain is not supported

Under certain conditions, you may have to move a computer that is running Microsoft Exchange 2000 Server or Microsoft Exchange Server 2003 Server from its current domain to a new domain. However, moving a computer that is running Exchange 2000 or Exchange 2003 from one domain to another is not supported. Additionally, running the /disasterrecovery Setup command against the Exchange computer object that was previously in a different domain is not supported.

There are typically two situations in which servers might have to be moved between domains.

A planned server move because of reorganization

We recommend that if you plan to move Exchange computers between domains within same forest, you install new servers into the new domain instead. The mailboxes can then be moved from the server in the old domain to the server in the new domain, and public folder content can be replicated.

Performing the move in this way will not disrupt mail delivery to the mailboxes that are being moved. Performing the move in this way will also avoid the potential data loss problems that are associated with other move methods that involve deleting and recreating the following:

• Mailboxes
• Server objects in the Active Directory directory service

For more information about how to move mailboxes in Exchange 2003, click the following article number to view the article in the Microsoft Knowledge Base:

An unplanned server move that is caused by a site failure, a domain failure, or a disaster

You can restore the Exchange 2000 or Exchange 2003 databases and mailboxes to a new Exchange-based computer that you installed in the new domain. To move the current Exchange information to the new Exchange-based computer, you must have a good backup of the databases that were on the failed server.

Note We do not recommend that you use the following procedure in situations in which you are trying to accomplish a �controlled� move between domains. Following these steps in that situation could cause e-mail outages, non-delivery reports (NDRs), and temporary mailflow problems. The effect on your specific Exchange organization should be tested in a lab environment. However, if you are already in a failure recovery situation in which a site or a domain has failed and the server must be rebuilt in a different domain, follow these steps:

1. Remove the server object of the failed Exchange computer from Active Directory.
   
   For more information, click the following article number to view the article in the Microsoft Knowledge Base:
   278918 How to manually remove a single Exchange-based server from Active Directory
2. Install Exchange 2000 or Exchange 2003 on the new computer by using the same name in a different domain. Apply all the required service packs and updates. When you install Exchange 2000 or Exchange 2003, make sure that you join the same Administrative Group of which the old server was a member.
3. Restore the Exchange databases from the backup of the original, failed server.

At this point, your new Exchange-based server will be installed. Restored databases should then be mounted. Clients should be able to connect to any newly created mailboxes on the server. However, clients that were connecting to the original server before the failure might have problems connecting to their mailboxes or sending and receiving e-mail. This behavior occurs because when the original server object was deleted in step 1 in the previous procedure, the user object attributes of users who had mailboxes on that server that were pointing to that server are no longer valid. There are three user attributes that must be examined and corrected for users who used to have mailboxes on the failed server. These attributes are as follows: For more information about these attributes and the syntax of their values, click the following article number to view the article in the Microsoft Knowledge Base: The easiest way to modify the user accounts in bulk is by using the ADModify utility. Use the ADModify utility to set the three attributes that were previously described for each user who had a mailbox on the failed server.

To obtain the ADModify utility, contact Microsoft Product Support Services (PSS). For more information about how to contact PSS, visit the following Microsoft Web site: To use the ADModify utility to set the three attributes for users, follow these steps:

1. Start the ADModify utility.
2. On the startup screen, click Modify Attributes.
3. In the Domain List, click the domain on which the user accounts are located.
4. In the Domain Controller List, click the domain controller.
5. Under Show Only, click to clear all the check boxes except the Users check box.
6. Click the green arrow button to bind to the domain. In the Domain Tree List, expand the containers to select the organizational unit container that contains the user accounts that have to be modified.
7. Click Add To List, click all the user accounts that have to be modified, and then click Next. When the next ADModify window opens, click the Exchange General tab.
8. Click to select the Set homeMTA check box and the Set homeMDB check box. Use the list for each attribute to set the attribute to the new server.
9. Click the Custom tab, and then click to select the Make a customized attribute modification check box.
10. Under Attribute Name, type msExchHomeServerName.
11. Under Attribute Value, type the following:
    
    /o=Your_Organization_Name/ou=New_Server�s_Administrative_Group_Name/cn=Configuration/cn=Servers/cn=New_Server_Name
    For more information about the exact syntax of the attribute value for the msExchHomeServerName attribute, click the following article number to view the article in the Microsoft Knowledge Base:
    296479 Requirements for disabling the Recipient Update Service
12. Click Go! after you make all the changes in the previous steps. The ADModify utility will make the required changes to the Active Directory objects that were selected in step 7.

Allow for time for Active Directory replication to be completed. After Active Directory replication is completed, the users should be able to log on to their restored mailboxes and send and receive e-mail.

For more information about backup and restore procedures for Exchange 2000, click the following article numbers to view the articles in the Microsoft Knowledge Base: