Change email using IOS mail app
I have a new email. I changed my appleid to the new one. Now I am updating my mail app. I deleted the old email from my phone and added the new email id. It is an outlook exchange email (old email was hotmail). When I bring up mail accounts, it still shows the old email under "Account". When I change that to the new one, it reverts back to the old one. When I send an email, it is still from the old hotmail id. Which is still valid and on my Microsoft account, but I updated the mail app and appleid and I want to eventually get rid of the hotmail id.
I can add the new email id - but technically (as Microsoft sees it) they are the same account, just different aliases. I didn't think adding a 'new email' would be the correct thing to do in this case, which is why I deleted the old and added the new.
How can I get my new email to be the primary email on IOS mail app? I have not updated my ipad yet.
iPhone 7 Plus, iOS 14