This tool resets customization that you've made to Outlook from the Outlook menu Preferences. It also restores Outlook window size and position settings. Set Default Mail App. This tool lets you choose Outlook for Mac as your default mail application. Then Outlook opens a new email whenever you click on a mailto: link in an email or website. Nov 23, 2017  Upon updating to macOS to High Sierra, Microsoft Outlook becomes incompatible, this video explains how to fix the issue.

Microsoft Outlook For Mac Versions

If you’re running version 15.32 of Microsoft Outlook for MacOS or lower, and have upgraded to MacOS High Sierra, you will receive an error that says “You can’t use this version of the application “Microsoft Outlook” with this version of MacOS“.

You can fix this problem with these steps.

1. Open Microsoft Word, Excel, or another Microsoft application.
2. Select “Help” > “Check for updates“.
   If you don’t see this option, or if you don’t have an option to update, download and install AutoUpdate.
3. Walk through the wizard to update Microsoft Applications. You will be able to upgrade Microsoft Outlook.

Microsoft Office For Mac

Once updates are complete, Microsoft Outlook will work in MacOS High Sierra.