Hosted Exchange requires a native mode Exchange organization

[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: 2009-09-23

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to determine whether the Exchange Server environment is configured as a Hosted Exchange environment. If the Exchange Server environment is a Hosted Exchange environment, the Exchange Server Analyzer queries Active Directory to determine whether the Exchange organization is running in mixed mode.

If the Exchange organization is running in mixed mode, a warning is displayed. Hosted Exchange solutions require a native mode organization.

After you switch to native mode you cannot switch back to mixed mode.

To switch to native mode

  1. Start Exchange System Manager: Click Start, point to All Programs, point to Microsoft Exchange, and then click System Manager.

  2. In the console tree, right-click the organization that you want to switch to native mode, and then click Properties.

  3. In <Organization Name> Properties, under Change operation mode, click Change Mode.

  4. In the warning dialog box, click Yes if you are sure that you want to permanently switch to native mode. Click Apply to accept your new Exchange mode.

To take full advantage of Exchange native mode, you must restart the Microsoft Exchange Information Store service on all the Exchange servers in your organization. You do not have to restart all the Microsoft Exchange Information Store services at the same time, but you must restart the service on each server for the server to take advantage of all Exchange native mode features. Restart the service on your servers after the change to native mode has been replicated to the local Microsoft Windows® domain controller.

To restart the Microsoft Exchange Information Store service

  1. Click Start, click Run, type services.msc, and then click OK.

  2. In the Services (Local) pane, find the Microsoft Exchange Information Store service.

  3. Right-click the service and then click Restart.

For more information about Hosted Exchange environments, see the following articles:

For more information about converting from mixed to native mode, see Microsoft Knowledge Base article 327779, "How To Convert from Mixed Mode to Native Mode in Exchange" (