DLP Policy Tip notifications are not displayed in Outlook for Windows

Symptoms

After you configure some data loss prevention (DLP) policies that include Policy Tip notification messages, you notice that the Outlook for Windows clients don't display the notification messages or that they display the wrong messages. However, Outlook on the Web (OWA) displays the expected notification messages.

Cause

This issue occurs because the compatible version criteria that's processed by the policy evaluator is based on the version of mso20win32client.dll, not the version of Outlook. In many cases, the version of mso20win32client.dll is not the same as the version of Outlook and Office.

For example, an administrator may configure a very restrictive policy that applies only to version 16.0.11727.20244 or a later version of Outlook. However, the policy evaluator uses version 16.0.11727.20222 of mso20win32client.dll and determines that the rule should not be applied. In this example, the rule would have to indicate the minimum required version of 16.0.11727.20222 to have the policy tip appear in Outlook.

Resolution

To make sure that Outlook applies all expected DLP policies, the administrator must verify that the Policy Nudge Rule for minRequiredVersion has a value that's not greater than the client-installed version of mso20win32client.dll. The mso20win32client.dll file could be located in either of the following folders:

  • C:\Program Files (x86)\Microsoft Office\root\vfs\ProgramFilesCommonX86\Microsoft Shared\OFFICE16
  • C:\Program Files (x86)\Common Files\Microsoft Shared\Office16

More information

In similar cases, the Outlook client can be forced to update the local policies and definition files. To do this, delete the following registry value from the "Policy Nudges" section of the indicated registry subkey:

Subkey: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\15.0\Outlook\PolicyNudges

Value: LastDownloadTimesPerAccount

Note

  • This troubleshooting step does not fix the problem that is caused by the condition that's described in the Cause section.
  • OWA isn't affected by the problem that's caused by the condition that's described in the Cause section.