Microsoft Office Insiders on Mac OS have something new to try on from Microsoft. The Fast Ring users of Microsoft Office are now getting a new build of Office on Mac OS.

The latest build of Microsoft Office on Mac OS is coming to Fast Ring users with version 16.38 and build number 20050602. It comes with some new features and improvements over the previous build which was released in late April. This update mainly focuses on Outlook for Mac OS.


New features

Add-ins for Outlook is now available

  • Install your favorite add-ins and enhance your productivity within Outlook.

  • You can install add-ins by going to the Customize Toolbar section within Outlook.

  • This feature is being rolled out gradually so if you don’t see add-ins just yet, please check back in a couple of days

Sensitivity labeling

    • When composing an email, you will now be able to apply a sensitivity label and view the default label if configured by your administrator.

    • You can add the Sensitivity button to the compose Toolbar via Customize Toolbar… or use Sensitivity in the top Draft menu.

    • For more information on this feature, please visit

Message List Improvements

  • Sender images in the message list are now available. Sender images can help improve scannability of incoming messages and help you quickly pick out email that is important to you.
  • You will see sender images in the message list when the message list is set to the Comfortable settings.

Mail Tips for Automatic Replies

Outlook will now show an information bar indicating when someone on your recipient list has their automatic reply turned on.

Bug fixes

  • Various improvements to app stability and performance

  • Message List: Improvements to keyboard navigation and VO prompts.

  • My Day: Performance improvements when displaying a large number of agenda items.

  • Calendar Events: Improved keyboard navigation for propose New Time.

  • Calendar Events: @Mentions now work when in the event compose form.