Jul 28, 2016 Manual uninstallation is available using the Microsoft Windows Add or Remove Programs option. This method requires a challenge‑response key, which is obtained from the DLPE administrator.' But without the DLP software, there is no method of getting the challenge-response key that they mention.
-->Note
Office 365 ProPlus is being renamed to Microsoft 365 Apps for enterprise. For more information about this change, read this blog post.
Original KB number: 2823261
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:
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
To work around this issue, force Outlook 2013 to download the updated DLP policies. To do this, follow these steps:
Use Registry Editor to remove existing DLP policies that are applied to Outlook 2013. To do this, follow these steps:
Exit Outlook 2013.
Click Start, click Run, type regedit, and then click OK.
In Registry Editor, locate the following subkey:
HKEY_CURRENT_USERSOFTWAREMicrosoftOffice15.0OutlookPolicyNudges
Delete the LastDownloadTimesPerAccount registry entry.
. Exit Registry Editor.
Start Outlook 2013, create a new message, and then type some text. When you do this, you force Outlook 2013 to download DLP policies.
Did this fix the problem?
For more information about DLP features in Exchange Online Protection, go to the following Microsoft TechNet website:
Still need help? Go to Microsoft Community.