Repeated password prompts in Outlook 2016 or Outlook 2013 for Outlook.com connected accounts
You may have received emails or have seen the posts in the community or in our support.office.com site about reconnecting Outlook 2016 or Outlook 2013 to Outlook.com for uninterrupted email access. However, when connecting your Outlook.com account to Outlook 2016 or Outlook 2013, you are prompted to log-in multiple times.
This may be due to having setup two-step verification on your account. To fix this issue, you will need to create an App Password to add the account in Outlook.
Please feel free to leave a comment in case if you have questions on solution provided.