ConvertDSNInternetContent registry key is configured to perform content conversion of all messages

[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: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine whether the ConvertDSNInternetContent registry value has been configured to perform content conversion for all messages that are received by the Exchange Information Store on the Exchange Server 2003 computer:

HKEY_LOCAL_MACHINE\ SYSTEM\CurrentControlSet\Services\MSExchangeTransport\Parameters

The Exchange Server Analyzer displays an error if the following conditions are true:

  • The ConvertDSNInternetContent registry value was manually created.

  • The ConvertDSNInternetContent registry value data is set to 1.

A value data of 0 or no value on the ConvertDSNInternetContent registry value disables content conversion of SMTP messages by the Exchange Information Store. A value data of 1 enables content conversion of all messages including SMTP messages on all SMTP Virtual Server Instances (VSIs) or to individual VSIs.

By default, the ConvertDSNInternetContent registry value is not created during an Exchange Server 2003 installation. The ConvertDSNInternetContent registry value can be manually created after the Exchange Server Server installation to change the behavior of content conversion on the Exchange Server 2003 computer. Generally, submitted SMTP messages must not undergo content conversion. If you enable content conversion for all messages including SMTP messages, you add processing overhead on the Exchange server. This additional processing overhead may cause performance and log file storage problems.

The Exchange Server Analyzer reports this configuration for informational purposes only. You must edit the registry to return the content conversion behavior on Exchange Server 2003 computer to the most efficient method of content conversion.


This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.

To correct this warning

  1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

  2. Navigate to the following registry key:
    HKEY_LOCAL_MACHINE\ SYSTEM\CurrentControlSet\Services\MSExchangeTransport\Parameters

  3. In the details pane, right-click the ConvertDSNInternetContent registry value, click Modify, and then change the Value data to 80. Click OK.


    To delete the ConvertDSNInternetContent registry value, in the details pane, right-click the ConvertDSNInternetContent registry value and then click Delete. Confirm deletion of the registry value by clicking Yes in the dialog box.

  4. Close the registry editor.

  5. Restart the Exchange server.

Before you edit the registry, and for information about how to edit the registry, see Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows registry" (

For more information about editing the Microsoft Windows registry see the following Microsoft Knowledge Base articles: