How to Mark a Message as Private in Microsoft Outlook
See Microsoft Outlook: Tips and Tricks for similar articles.
If you need to send a message that you want the recipient to understand is private information, you can mark the message as private by following these four steps.
This feature works the same in all modern versions of Microsoft Outlook: 2010, 2013, and 2016.
- From the Message Ribbon of the message, select the Tags group Dialog Box Launcher.

- In the Properties dialog box, from the Settings section, select the Sensitivity drop-down arrow.

- Select Private and click Close.

- When received by the recipient, the message will indicate that it should be treated as private.

