Microsoft Office 365: Data Loss Prevention (DLP) Service

Data Loss Prevention (DLP) in Office 365 (Exchange Online) is used to prevent people from accidentally sending sensitive information, such as credit card or Social Security numbers, via email by using Policy Tips as a reminder. Similar to Mail Tips in the Outlook client, Policy Tips only show up if content in the sender's email message violates a DLP policy such as in the example below.

After sending the email with sensitive information, you will also receive an email from postmaster@uwrf.edu warning that you have sent sensitive information in your email. Your email will not be blocked or changed in any way, it is merely an informational warning about the risks involved.

If you do not see a policy tip when entering sensitive information in an email or the tips are not working after a change to the DLP policy was made, there may be several causes:

  • Policy Tips only work in Outlook 365, Outlook on the web or OWA for Devices.
  • Policy Tips are dependent on the full Office 365 Suite being installed on a computer. If Outlook 365 alone is installed, the tips will not work.
  • For Policy Tips to appear, Mail Tips in Outlook 365 must be enabled. This setting is found at File > Options > MailTips.
  • Outlook 365 checks for changes to DLP policies once every 24 hours. If an Outlook client does not seem to be behaving according to policy after a change, make sure that it has been at least 24 hours since the policy change was made. 

Check out DLP information (including a video) provided by Microsoft.