send message with O365+OAuth2 hangs indefinitely on Thunderbird 91.11.0 (windows x64)
I have been successfully using Thunderbird with O365 and OAuth2 since my organization reconfigured for 2FA back in April 2022. Each time I need to reset/change my enterprise e-mail password I must reset my OAuth login, which I did successfully once before by simply deleting saved logins and then re-completing the 2FA process.
After doing that again last week I can no longer send e-mail from TB 91.11.0 -- it successfully connects to smtp.office365.com and then hangs indefinitely on "Sending message...". IMAP is functioning normally (receiving e-mails, moving messages between server folders, etc.). I first confirmed that my (well-documented) my working SMTP settings were not changed.
What I have done to research the issue:
- confirmed that security.enterprise_roots.enabled = true (and all org-specific certs are shown) and I have turned up these Iog levels to 'All': mailnews.oauth.loglevel, mailnews.send.loglevel, mailnews.smtp.loglevel
- in preferences, confirmed that cookies are accepted from: https://login.microsoftonline.com, https://outlook.office365.com
The error console shows that my TB receives a successful response from the authorization server with a access token (and is refreshing on intervals afterward). When I send a message, the console reports successfully connecting to smtp.office365.com and then simply waits forever without any apparent timeout. When I cancel sending the message, the console reports the socket to the SMTP server is closed. No further detailed information is emitted into the console. I need help with diagnosing the problem further to understand why no progress is made.
I have also tried the following to fix and also re-confirm this issue:
- created a full backup of my profile folder
- deleted any passwords and/or OAuth2 authentication tokens Thunderbird has remembered for the troubled account
- deleted any O365 related cookies
- deleted the subject account
- restarted Thunderbird
- re-created the subject account using manual account setup, and specifically for SMTP: smtp.office365.com:587 with STARTTLS and OAuth2, user name in format 'firstname.lastname@example.org'.
It was working before. After resetting my password and completing the 2FA process, sending e-mail simply stopped working and I am not sure how to proceed.
Any suggestions for other settings to check as well as how to get TB to emit more detail in the console would be greatly appreciated.