You can use NexTags.exe to capture requests and responses between the device, Exchange ActiveSync and Exchange.

To use NexTags:

1. Run Nextags.exe on the server that is running Exchange ActiveSync. This is usually your Front End server if you have one. If you don’t have a Front End server run the utility on your mailbox server.

2. Click on the Options tab and check “Trace output to file”, and in the "File Name" box, specify a filename. The default is c:\massync.log

3. Set "Trim Percentage" to 30%.

4. Set "Limit file size to" to 10MB.

5. To capture logs for all users use * in the "User Names" field. To
Capture the log for individual users, type the user aliases separated by a
semicolon (;).

6. Make sure that the “Do Not buffer” check box is unchecked.

7. Click "Tags", and then click on “Errors”, “Warnings”, or “User” depending on the error you are trying to troubleshoot. You can also click on “Check all”. This logs everything and could impact performance.

8. Click "Enable Tracing".

9. Click "OK".


After you complete this configuration, the Exchange server records all the logging information to the file that you specified on the "Options" tab. This log can be useful to troubleshoot synchronization failures.

When you have finished troubleshooting the issue, make sure you turn off tracing by clicking on “Disable Tracing” and clicking OK .