Once it is opened successfully, close it, and relaunch it in the normal mode.Just press and hold the Shift key on your Mac and launch Outlook.For instance, it can keep checking the scheduled emails or sending/receiving some attachments in the background. Sometimes, while launching the app, a connectivity-related process can make Outlook not working. Solution 2: Run Outlook without Connectivity Try launching Outlook again after it restarts.From here, you can restart your Mac without any trouble.Just go to the Finder and click on the Apple logo on the top.This will reset its present power cycle and cache automatically, fixing app-related issues with it. If Mac is blocking Outlook from opening, then a simple restart would be able to fix it. Here are some of the simple ways to fix Outlook not opening on Mac.
This can happen due to a firmware issue with Mac or the Outlook application. Chances are that even after some attempts, Outlook might not open or launch on your system.
This is one of the most commonly faced Outlook related issues with Mac.