I have an issue where its seems like one of my email accounts cannot get the correct password. I have been using ChatGPT for help and here is its summary of the issue - Description: I’m using Thunderbird (latest version) on Windows and have two Outlook 365 accounts configured: a1@adagioconcepts.com (hosted via Office 365 from GoDaddy) — fully working a2@floetermusic.com (also hosted via Office 365 from GoDaddy) — receiving works via POP3, but sending via SMTP fails Both accounts are configured identically: SMTP server: smtp.office365.com Port: 587 Connection Security: STARTTLS Authentication Method: OAuth2 Username: matches the email address For a2@floetermusic.com, Thunderbird errors when I try to send email (wrong password). I have re-entered the password many times with no change in behavior. However, the other account (a1@adagioconcepts.com) authenticates and sends perfectly using OAuth2. I have: Confirmed that the SMTP server is assigned correctly to the failing account Reset Thunderbird’s login store (logins.json, key4.db) Deleted and re-added the SMTP entry Ensured both accounts use OAuth2 Verified that App Passwords are not available in my Microsoft 365 tenant (modern auth only) Thunderbird is clearly capable of handling OAuth2 SMTP with one account, but won’t initialize it for the other. Can anyone help determine why OAuth2 SMTP does not initiate for one account while working on another with identical settings and provider? Thanks,