old apple id accounts with invalid email address
years ago I had a Apple ID account on my iphone 5, I change to another email account because my old email address is invalid now and I did not log out of the old account first, now my phone is stuck with a invalid email account that I cannot sign in or out of so I can update my account to the new email address. I set up a new Apple ID account and changed to my new iphone 6s plus...but it only recognises my old email address
iPhone 6s Plus, iOS 11.2.6