How to re-add “reserved domain” email with all my Xbox info

Hi. My name is Brilliant and I am happy to assist you today.

Here is a thread with more details on the issue you're currently facing: https://answers.microsoft.com/thread/86f96033-cb7b-4203-90ae-b70090312c66

It states that:
Unfortunately, if you're getting an error, "Account does not exist" when trying to sign in, the account is effectively closed. Once an account is closed, there is no way to recover said account. Microsoft also does not recycle email addresses once they are closed, so one cannot use the same account to sign up for a new one.

I hope this helps resolve your query.

While still logged into your account, click "Your info" and then select "Manage how you sign in to Microsoft." Then Click on "Add email" and create a new Microsoft domain email address or add an existing Microsoft email address. 😁

Thanks for the reply, I tried adding my new account to my old xbox account that but it says "This email is part of a reserved domain. Please enter a different email address."

This email address is included in a reserved domain. Please enter a different email address.

In addition, whenever I try to change my alias and take my xbox email and make it an alias to my bing account, it says "This email is part of a reserved domain. Please enter a different email address."