The SuppressStateChanges registry value must be changed

[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: 2011-07-29

The Microsoft Exchange Server Analyzer tool enumerates all existing Routing Group Connectors in the current Exchange organization.

When the tool detects an existing Routing Group Connector that connects from an Exchange Server 2000 Routing Group to an Exchange Server 2007 Routing Group or from an Exchange Server 2003 Routing Group to an Exchange 2007 Routing Group, and the SuppressStateChanges registry key value is not present or is set incorrectly, the tool generates a warning message that resembles the following:


It is recommended to set the SuppressStateChanges value located in registry key RegistrySubKeyPath to 1 on server ServerName to avoid mail loops.

To address this issue, you must set the SuppressStateChanges registry key value correctly.

To set the SuppressStateChanges Registry value
  1. Open registry editor.

  2. Move to the following registry key:


  3. Right-click Parameters, select New, and then select DWORD value.

  4. Name the new DWORD value SuppressStateChanges.

  5. Double-click SuppressStateChanges.

  6. In the Value data field, enter 1, and then click OK.

For more information about Routing Groups, see Understanding Routing Groups.