This account is not supported in Outlook for Windows due to the license provided by your work or school

Hopefully someone from Microsoft is taking a look at this issue. Just to go on record. Outlook works great with my personal account. The second account that fails is a fully licensed Outlook account. So having a "legitimate license" is not the issue. We own and pay for both license. Thank you for putting some resources behind this and getting it fixed.

I tested it just now. As soon as the mailbox itself isn't tied to apps (i.e. Outlook for Desktop) by virtue of a license that "includes" the desktop apps, you cannot add it. So, that basically means their entire Exchange Online (which seems to be mostly the Basic users) user base (where users previously were able to add their account to Outlook, let's say if they had a Home & Business license), they can no longer do so going forward. It doesn't matter if they already have a separate, valid license for Outlook. So, in my scenario:

* I already have Microsoft Office 2021 Home and Business. Which grants me a license to use Outlook for Desktop. I have no "personal" mail accounts such as Gmail etc. So I have, at this point 1x Outlook license.

* I have ONE Business Standard license for my work e-mail (which gives me Exchange Online and grants me ANOTHER license to use Outlook for Desktop, on the same PC). So at this point, I have "2x" Outlook licenses. One occupied by this e-mail address, one left.

* I have ONE Business Basic license for a another e-mail (which gives me Exchange Online but NO desktop apps). So, at this point, I SHOULD be able to add this account because I have 1x Outlook license still left. But I can't. I can no longer add a second "business" e-mail, because "it doesn't have a separate (in my case, therefore, 3rd) license for apps (i.e. Outlook)".

The takeaway is: You can no longer add a mail account in the new Outlook if said mail account doesn't come with its OWN Outlook (apps) license.

This is ridiculous beyond understanding. Unacceptable to the point that if they don't fix this, I'll cancel BOTH Exchange licenses and move over to Google Business with my domains. Based on THIS interpretation though, they should therefore BLOCK adding 3rd party mail services, as they don't come with Outlook licenses! I'll give it a few days and then decide.

Microsoft as always doing what it can best - ruining its own products. Seems like it's Outlook's turn this time. Such a big company and so incompetent with completely disregard for its users. Money and ads seems number one priority in Microsoft and it really shows in their deeds... Shameful.

I'm sorry, but I don't agree with the argument posted here that suddenly EVERY mailbox must (seperately) be tied to a license with apps. Since when is that the case? A user could always before be in the situation where they paid for exchange online + desktop apps (e.g. 365 Business Standard) and then take out another domain with exchange online only, and add that mailbox to the same Outlook profile.

Of course, if you had used that single mailbox (without apps) on a device where there is NOT YET a licensed Outlook app, it would make sense. But we're talking about a use case where there is an existing, fully licensed Outlook, and people are just trying to add more (fully licensed) exchange accounts.

What's next? Is Outlook going to block adding Zoho mail because "they don't come with a license to use Outlook"? Or Google mail? It makes no sense. This issue started occuring when the new Outlook went from "preview" to "new" status. It's clearly something else.

We are experiencing the same issue; I changed a license from basic to standard and it seems to work. But now I'm trying to do it for the other email we're having an issue with and it's not working. I've submitted a ticket but I highly doubt they'll have an answer for me today.