After you make a change to a data loss prevention (DLP) policy, the change doesn't take effect in Microsoft Outlook 2013 in Office 365. For example, you experience one or more of the following symptoms:
Policy tips aren't displayed correctly when the conditions in the DLP policy are met.
Messages aren't appropriately blocked by the DLP policy.
You experience these symptoms even though the DLP policies were working correctly before the change was made.
This problem occurs if the updated DLP policy wasn't downloaded to Outlook 2013. Outlook 2013 checks for changes to DLP policies one time every 24 hours.
Important This section contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, see the following Microsoft Knowledge Base article:
322756 How to back up and restore the registry in Windows