If you're using TB to get to your outlook.com email, your problem may be related to the fact that Microsoft just flipped the switch to stop accepting basic authentication (just username and password) on their website from applications - including older versions of MS Outlook. I had this problem with Outlook 2019. You can google: "Microsoft Outlook Basic Authentication" for more information. But if this is the cause, and you are using TB to access your email, all you should have to do is go to the setup for each of your email accounts in the latest version of TB (which supports advanced authentication) and change the authentication method to OAuth2. That is the modern authentication method that MS accepts now. You may have to also login to your email account online (outlook.com) to add 2 factor authentication on each account first. If the first step doesn't work, try the second step and retry the first one. I talked to several MS support techs before I got the correct steps. Good luck!