Deleted emails

We have been trying to change the details on an xbox account that had my husbands email attached to it as we wanted to put our son's details on it as he's the only one that. uses it. My son set up an alias on outlook I think and in changing the account over my husbands email address has been deleted and all his old emails are now in my sons alias account. My son's alias account won't send emails and my husband can't log into his email as it's now saying that account doesn't exist. Could someone help to sort this out please.