Step 1: Check the Outlook for Mac version number
- On the Outlook menu, click About Outlook.
- View the version number that is listed.
- If your Outlook installation is not at version 15.23 or a later version, install the June 14, 2016, update for Outlook 2016 for Mac or a later update. For information about this update, go to the following article in the Microsoft Knowledge Base:3165798 MS16-070: Description of the security update for Office 2016 for Mac: June 14, 2016
Step 2: Disable the preview feature
- Exit Outlook.
- Open Terminal by using one of the following methods:
- Make sure that Finder is the selected application, click Utilities on the Go menu, and then double-click Terminal.
- In Spotlight Search, type Terminal, and then double-click Terminal in the search results.
- Type the following commands in Terminal, and press Enter after each line:
defaults write com.microsoft.Outlook DisablePreviewForSMIME 1
- Exit Terminal.
- Start Outlook.
Article ID: 3172627 - Last Review: Jun 23, 2016 - Revision: 1