Microsoft Outlook Won’t Open On Mac: Here’s How To Fix It
There are a plethora of email client options available for Macs, each offering their own benefits and drawbacks, andMicrosoft Outlooksure is one of them. Because despite the title, Outlook isn’t limited to functioning on Windows hardware — plus it hasseveral helpful shortcutsyou may not find in other potential email services.
But ultimately, just like any other app or software that exists, Outlookisn’t immune to bugs and glitches. These errors can result in all sorts of headaches from the inability to find messages to crashing in specific browsers. They can even keep you from accessing your email entirely.

If you’re using Outlook on a Mac and suddenly find yourself unable to get it to open, don’t worry: There are several reasons this could be happening and just as many ways to fix the problem. Just take a deep breath, then go down the list one item at a time until Outlook loads up properly once more.
The usual suspects
First and foremost, see if the usual glitchy software fixes have any effect. Double-check for any new updates before doing anything drastic.
Updating may not work (or be an option in the first place) however, in which case your next course of action should be reinstallation. Delete Outlook from your Mac by dragging the application icon to the Trash and emptying it, then download and install Outlook again from the App Store — be aware that, if Outlook does start up again with this method, you may need to sign back into your account.

Fix your Outlook profile
Another possibility is that your Outlook profile itself may have been corrupted, in which case you can repair it but you’ll want to verify whether or not it’s actually corrupt first.
Once the repair is finished (this may take some time, so be patient), Outlook should be good to go. If not, you’ll need to dig a little deeper.

Try Disk Utility
Your Outlook troubles may have something to do with your Mac’s internal disks (i.e. storage drives), in which case Disk Utility may be able to sort the problem out. But be aware that running Disk Utility can take anywhere from several minutes to several hours, depending on a number of factors.
If you’ve tried all of the previous methods and gave Disk Utility a shot, but Outlook still won’t open, there’s still one more potential fix you can try.
Turn off Encrypted Email previews
Previews for encrypted messages are turned on in Outlook by default, but there’s a chance they might be causing the app to crash or otherwise not function. If this is the case, turning previews off should fix the issue.
In the event that Outlook still won’t open, even after attempting all of these fixes, the problem may not be on your end. Give it a half hour, hour, day, etc and try again to see if the issue has sorted itself out. In the meantime, if you have access to Outlook on other platforms (i.e. a smartphone, PC, etc) you can use that as a temporary workaround.