Enhanced performance, designed for simplicity – the new Outlook for Mac

Update on Mac Business channel Beta ↯

There was a whole big dump of new versions of everything over the weekend and I got outlook set up and working simultaneous with a legacy enterprise exchange account, my "work or school" Microsoft account, 2 personal Microsoft accounts (both on a shared Microsoft Family plan), 2 unrealted personal Gmail accounts. One after another, with no issues. All working together.

NOTE:

I had to remove all the App Store versions before hand.  Also, I'm on macOS Sequoia 15.1 (Beta) (I'm sure the new macOS has a role in this) and a Microsoft 365 Premium Business subscription that includes Copilot 365. All installed and maintained locally on the Mac using Microsoft's Auto update (see below). Using Microsoft Edge Dev edition logged in as Work account, linked to my Personal account, ie it shows "Linked" with using web versions and Copilot (getting the ZTN wrapped around everything first, *may* be the key here). 

Your experience may vary based on your specific setup and subscription type. If you're an admin or an individual  subscriber (like me), MS support has been outstanding, being proactive at times,  calling me to offer support, when I didn't immediately setup Copilot after purchasing.