Looking carefully at your documented instructions I have every setting correct except in the outgoing SMTP server I can select connection security to STARTTLS but i do not have the option available for OAuth2 in the drop down list for Authentication?? What do I do as I have updated Thunderbird to the most recent available for my 32 bit version of Linux which is 68.10.0 which it appears cannot connect to my Hotmail mail service. I do have OAuth2 available on server settings strangely enough but not in outgoing SMTP server settings.