If you are using an exchange email and having any of the following symptoms with Outlook 2016 or Office 365:
- Not accepting your password and keeps prompting for your password
- A message saying “Your mailbox has been temporarily moved on Microsoft Exchange server. A temporary mailbox exists, but might not have all your previous data. You can connect to the temporary mailbox or work offline with all of your old data. If you choose to work with your old data, you cannot send or receive email messages.” With options Use Temporary Mailbox or Use Old Data
This fault is due to an Microsoft Office update and it looks like Microsoft is forcing 365 login for auto discover.
If you are using the same email account for your Microsoft Office 365 admin account and your email account, this seems to be causing the issue.
You could try changing the Microsoft Office 365 admin account email but this can be tricky. I would advise to go with the registry solution above which is much easier for now until Microsoft fix the issue.