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

Same issue, can't get past email setup & trying to setup the same account, I get account already setup & still won't go past the setup screen.

?????

Changing your primary alias doesn’t really affect the functionality of your Microsoft account. You can still use your personal email as a secondary alias to sign in anywhere. It just gives you more functionality if you sign into the new outlook with the @outlook.com alias.

If by "more functionality" you mean "the ability to use the app" then we are in agreement. When i use my personal email as my primary alias the app is unusable. Not in terms of inconvenience or that i have a complaint, but that it's void of functionality, i can't access the interface beyond the login screen. (Unlike every other MS product i've used). I can't add my MS account, using either my personal email address or my MS address. This is after weeks of troubleshooting every permutation of adding/removing/repair resetting/olk command line stuff suggested by in-app support, on multiple computers. When i change my primary alias back to my MS email, everything works fine, but i lose a feature - the ability to use my personal email address.

My usage of a primary alias is completely irrelevant to any other MS product i use. Stated differently, email is the only reason i'd have my personal email set as my primary alias, or even associated with my MS account. In the "old" mail app, outlook android, and outlook.com, i can set the "from" field to my personal email address rather than my MS account email. Setting my primary alias to my personal email address makes my personal email the default, so i don't have to specify it each time. In the new outlook, setting the "from" field to my personal email address is not something i can do. When i add my MS account to the new outlook (which again, i can only do when my MS email is my primary alias), my personal email address is not in the "from" dropdown.

In short, i can't use New Outlook if i have my primary alias set to something other than my MS/outlook email address, and i can't use secondary aliases in the New Outlook. I guess i'll narrow my original statement to: New Outlook is incompatible with aliases. That's the experience i'm having, anyway.

Changing your primary alias doesn’t really affect the functionality of your Microsoft account. You can still use your personal email as a secondary alias to sign in anywhere. It just gives you more functionality if you sign into the new outlook with the @outlook.com alias.

The issue for me is the use of an alias. My @live.com address is only for MS services/logins. With outlook.com, Outlook Android, and the Win11 Mail App i've used my personal email as my MS account Primary Alias. This app on the other hand is essentially incompatible with Primary Aliases.

Good, glad it worked for you.