I have an email address at an organization that uses Office365. I am able to log in, read and send emails using Outlook either as a standalone app or through a browser. I can also do the same on my desktop with Thunderbird. It's version 102.6.1 (64-bit) running on Windows 10. I must have logged in ages ago and I don't need to do it daily. I use the 2FA mandated by my organization when I log in with Outlook. Thunderbird is so much better in many ways that I'd like to use it on my laptop as well, but when I try to set it up, it just replies with "Authentication failure while connecting to server outlook.office365.com" even though even the 2FA succeeds. This is a laptop with Windows 10 and TB 102.7.0 (64-bit) I have checked that (suggestions from other threads): -Cached connections is 1 -IPv6 disabled -Cookies enabled -I cannot set up a app password. I guess not allowed by my organization. Settings are typical, server outlook.office365.com, 993, SSL/TLS, OAuth2. All that works on TB on the other computer. Thanks for any suggestions!