I'm trying to configure thunderbird to access my email via outlook 365. Security settings are set up with 2FA and no app passwords, so that is not an option. I've setup IMAP with oauth2 and that is working fine to receive mail and even store drafts on the server. However when I try to send emails via SMTP I'm getting an error that thunderbird cannot log in with username. SMTP is setup with starttls and oauth2. I tried SSL/TLS but connection times out, I also tried normal password but that fails as well. Also, when it fails to connect there is a button "enter new password" but that doesn't ask for password and just closes window second time around. The office 365 security page is not logging a failed login attempt. My main suspicion is that thunderbird ignores oauth2 over starttls, but not sure how to check what it's actually trying to do. I tried the latest 72.2.2 and 81.0b4, same behavior. I also tried removing the account as well as removing the whole thunderbird directory, to no avail. System is OsX Catalina. Apple mail and iphone manage to login to account.