Duplicate Microsoft Exchange System Objects container exists in Active Directory

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at https://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2005-11-17

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to determine whether the Microsoft Exchange System Objects container exists in the Domain Naming context.

If the Exchange Server Analyzer discovers a duplicate Microsoft Exchange System Objects container exists in Active Directory, the Exchange Server Analyzer displays an error: "Active Directory domain appears to be prepared for Exchange but there are multiple 'Microsoft Exchange System Objects' containers in existence. Clean up may be necessary."

This issue may occur in Exchange Server environments in which:

  • A 2-way Active Directory Connector (ADC) server Connection Agreement from Active Directory to Exchange Server 5.5 was deleted and replaced.

  • A new 1-way ADC server Connection Agreement from Exchange Server 5.5 to Active Directory is in place.

  • A mixed-mode environment running Exchange Server 5.5 was migrated to an Exchange Server 2003 environment.

  • A migration to Exchange Server 2003 from a foreign mail server has been performed.

When the Exchange Server Analyzer displays this error, you must delete the incorrect duplicate Microsoft Exchange System Objects container or organizational unit (OU). When a duplicate Microsoft Exchange System Objects container exists, you cannot solve the problem by running DomainPrep again. You must identify and delete the incorrect duplicate Microsoft Exchange System Objects container.

To remove the duplicate Microsoft Exchange System Object container

  1. Log on to the domain controller with administrative credentials.

  2. Click Start, click Programs, click Administrative Tools and then click Active Directory Users and Computers.

  3. In the Active Directory Users and Computers management console pane, click View from the toolbar menu and select Advanced Features.

  4. In the Active Directory Users and Computers management console pane, locate the incorrect, duplicate Microsoft Exchange System Objects container or organizational unit (OU).

  5. Verify the incorrect, duplicate Microsoft Exchange System Objects container or OU does not contain valid Active Directory objects.

  6. Right-click the incorrect, duplicate Microsoft Exchange System Objects container or OU and then click Delete.

  7. Confirm the deletion by clicking Yes in the Active Directory dialog box.

    Note

    If you want the change to be replicated immediately, you must manually initiate replication between domain controllers.

For more information about this issue with Exchange Server, see the following Microsoft Knowledge Base articles: