Exchange ActiveSync tracing is currently enabled

[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 if tracing has been enabled for Exchange ActiveSync®:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft Server ActiveSync\MasSync\Enabled

If the Exchange Server Analyzer finds the value for Enabled is present and configured with a value greater than 0, a warning is displayed.

Exchange ActiveSync is implemented as an Internet Server Application Programming Interface (ISAPI) extension in Internet Information Services (IIS). IIS, Exchange ActiveSync, and many of the client devices that use Exchange ActiveSync include native tracing capabilities, thereby obviating the need to use the native tracing capabilities of Microsoft Windows Server™ 2003.


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: HKLM\Software\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft Server ActiveSync\MasSync

  3. Delete the Enabled value.

  4. Close the registry editor and restart the Exchange Server computer for the change to take effect.

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

For more information about tracing and logging for Exchange ActiveSync and Exchange ActiveSync clients, see the following Knowledge Base articles: