Same here for the last few days with all my Outlook accounts. Thinking passwords out of date, changed all passwords to Apple complex ones now stored on password manager, thought it was MS changing login from login.live.com to account.login.live.com, added both in passwords, not this either, even prompted when mail going into settings, weird. Have re-added in email accounts, not that. Tempted to remove my outlook accounts and re-add but people have said that doesn’t work either. Have been abroad so checks I had connected to home country in vpn just in case it was a security issue not that. Have reported to Apple. Annoyingly if facial recognition fails (not looking) when prompted for passwd going into passwords store the whole thing stops and have to cancel the password prompt to enjoy it another time. Still waiting for an answer but 17.1.1 might have been the trigger for this or just that the upgrade happened. Don’t get me going on text editing “improvements” I can’t select any point in a word to position the cursor anymore without selecting a whole word or Linton g somewhere else and moving the pipe where I want it. Apple, sort it out please, basic features are degrading again!!