iMac screen flickers when using Outlook for Mac

Last Updated: July 23, 2019


We have identified an issue where macOS (primarily running Mojave) screen flickers on some of the iMac machines when using Outlook for Mac.


You are most likely using an iMac (Retina 5K, 27-inch) machine. While using Outlook for Mac, the screen flickers and you need to reboot the machine to clear the issue.


Apple has identified the root cause for this issue and has addressed it in their upcoming major macOS release (macOS Catalina version 10.15). Until this release is generally available, users are advised to apply the workaround described below.

Open Outlook in Low Resolution Mode. We understand this is not an ideal workaround, but it can help until the release of macOS Catalina version 10.15.

Setting Low Resolution Mode
  1. Quit Outlook.

  2. Go to the Applications folder.

  3. Select Outlook.

  4. Go to Get Info by performing one of the following tasks:

    • Right click Outlook and go to Get Info.

    • Left click Outlook, choose file, and select Get Info.

    • Left click Outlook, press the Command key and the letter I.

  5. From the new window, check the box next to Low Resolution Mode.

More Resources

Icon Experts (brain, gears)

Ask the experts

Connect with experts, discuss the latest Outlook news and best practices, and read our blog.

Outlook Tech Community

Icon Community

Get help in the community

Ask a question and find solutions from Support Agents, MVPs, Engineers, and Outlook users.

Outlook Forum on Answers

Icon feature request (light bulb, idea)

Suggest a new feature

We love reading your suggestions and feedback! Share your thoughts. We're listening.

Outlook UserVoice

Expand your Office skills
Explore training
Get new features first
Join Office Insiders

Was this information helpful?

Thank you for your feedback!

Thank you for your feedback! It sounds like it might be helpful to connect you to one of our Office support agents.