I have a Microsoft account and in building a website for a friend, we gave him an email address at his domain. I logged into my Outlook and, NO PROBLEM, his email account displayed beneath mine in outlook. BTW, a message popped up around this time about authenticator added security blah blah. I added it. Open the Outlook app, close it, open it, close it a couple of times, and BOOM!!! You need to re-login. Ok, no prob AUTHENTICATOR, check my phone and it works. But then the other email I gave him needs re-login and after 5 days and probably 4-6 STRAIGHT hours of troubleshooting, mind you while I need info from this email because I'm building a website. Nothing. He doesn't get a notification, I don't. Can't log in.