Mac New Outlook Sync Issues

Copper Contributor

Hello, I have ~55 Mac users running MacOS v12.x or v13.x. All use Office 365 with either the Old Outlook or New Outlook, depending on their preference.


In the past year, probably 10-12 New Outlook users have encountered sync issues whereby the New Outlook stops receiving or sending email. I switch them back to the Old Outlook and all works just fine.


A few days later the user switches back to the New Outlook and it "might" start syncing again. It's hit or miss.


The only way I've gotten the New Outlook to sync again is to completely uninstall Office 365, including the related System Preferences, and reinstall Office 365.


Has anyone encountered a fix for the Mac New Outlook syncing issues?


Thank you...

2 Replies


I search a post at past, worth to take a look on suggestions:


Outlook for Mac sync issues - Microsoft Community Hub


I discovered with 6-7 users last week that when the New Mac Outlook quits syncing (sending or receiving), the user can switch back to the Old Outlook and let their 365 email download, which can take hours. Then a day or two later, the user switches back to the New Outlook and syncing works.


Not sure why this works. I know it’s not the solution, but was hoping someone had a “do this in the New Outlook” fix to avoid switching back and forth between the New and Old Outlook.