Outlook 2016 for Mac freezes on email folders that contain several encrypted messages


In Microsoft Outlook 2016 for Mac, when you navigate to a folder in which several encrypted email messages are displayed in the message list, Outlook freezes or experiences other performance issues.


To fix this issue, update Outlook 2016 for Mac to version 15.23 or a later version. Then, disable the preview feature for encrypted email messages by running a command in Terminal. To do this, follow these steps.

Step 1: Check the Outlook for Mac version number

  1. On the Outlook menu, click About Outlook.
  2. View the version number that is listed.
  3. 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

  1. Exit Outlook.
  2. 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.
  3. Type the following commands in Terminal, and press Enter after each line:

    defaults write com.microsoft.Outlook DisablePreviewForSMIME 1

    killall cfprefsd
  4. Exit Terminal.
  5. Start Outlook.

文章 ID:3172627 - 上次审阅时间:2016年6月23日 - 修订版本: 1

Microsoft Outlook 2016 for Mac