The administrative group mode is unknown

[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]  

Topic Last Modified: 2005-11-17

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to verify the mode of the administrative group by checking the msExchAdminGroupMode attribute of the administrative group object in the Administrative Groups container in Active Directory. If the Exchange Server Analyzer finds that the value for the msExchAdminGroupMode attribute does not equal 0, 1, or 2, an error is displayed.

Exchange uses the mode of the administrative group to indicate whether the administrative group can include Exchange Server 5.5 servers or Exchange Server 2003 servers (or Exchange 2000 Server servers). If a value that is not 0, 1, or 2 is present for this attribute, it is likely an administrator has manually changed the value. Exchange Setup or Exchange System Manager will not set this value incorrectly.

You must correct the value using a tool such as the Active Directory Service Interfaces (ADSI) Edit snap-in, the LDP (ldp.exe) tool, or any other Lightweight Directory Access Protocol (LDAP) version 3 client.


If you incorrectly modify the attributes of Active Directory objects when you use ADSI Edit, the LDP tool, or another LDAP version 3 client, you may cause serious problems. These problems may require that you reinstall Microsoft Windows Server™ 2003, Exchange Server 2003, or both. Modify Active Directory object attributes at your own risk.

To modify the MSExchAdminGroupMode attribute

  1. Using an Active Directory editor, such as ADSI Edit, to locate the administrative group object in Active Directory.

    The MSExchAdminGroupMode attribute can be found at:

    CN=Configuration, CN=Services, CN=Microsoft Exchange, CN=Organization, CN=Administrative Groups, CN=Administrative group

  2. Type one of the following integer values:

    0=native mode (the administrative group was created using Exchange 2000 Server or Exchange Server 2003)

    1=Exchange Server 5.5 mode (the administrative group was created using Exchange Server 5.5 and includes only Exchange Server 5.5 servers)

    2=mixed mode (the administrative group may include both Exchange Server 5.5 servers and Exchange 2000 Server or Exchange Server 2003 servers)

For more information about using the LDP tool, see Microsoft Knowledge Base article 260745, "XADM: Using the LDP Utility to Modify Active Directory Object Attributes" (

For more information about working with ADSI Edit, see the topic "Adsiedit.msc: ADSI Edit" in Windows Server online Help.