New Outlook won't let me add my outlook email account.

I'm having this same issue and have tried everything I can think of. My account that I'm trying to log into the new outlook is an outlook account. When I try to sign into it on the app it loads for a long time and then states "Outlook does not yet support adding Shared Mailboxes this way. Try adding another account." I'm not able at all to figure out what this means or how to fix it.

How come they didn't fix this problem??? It's been reported since August 11 2023. I'm considering switching to google services for cloud and everything else.

I keep getting sent back to the begining, Outlook let me add one of my Email addresses but not the 2nd. I also was able to get into my 365 account ( finally ) but that did not help

This same issue happened on my Outlook Office app. My son-inlaw, ( Microsoft employee ) also failed to get the account add. Also contacted my Service provider with no help.

I use to have this all work, but believe the issue started with an update from Microsoft.

Thanks @TinkerUK. I would like Microsoft to continue to allow alias email addresses and fix this.

Do you have Microsoft 365? Maybe thats the problem.