smtp.mail.yahoo.com
 Port 465
 SSL/TLS
 Authentication method OAuth2
 User name johngherrett@yahoo.com

I've used TB successfully for many years to access several Yahoo and Googlemail accounts. Windows 10. Recently the Yahoo accounts don't work so I've tried several times deleting and reloading them. This may be a red herring but the trouble seemd to start when I installed TB on a new Windows 11 laptop and failed to load the Yahoo accounts. I've tried following both Mozilla and Yahoo help articles but ultimately success is partial at best (i.e. incoming works, outgoing fails) This is the sequence I have followed 251128 tried this: Deleted all yahoo accounts in Thunderbird Edited outgoing yahoo server to smtp.mail.yahoo.com Port 465 SSL/TLS Authentication method OAuth2 User name johngherrett@yahoo.com Added yahoo account johngherrett@yahoo.com name and email address opens yahoo! login sequence enter email and yahoo account password - FAILS logged out of Yahoo mail open elsewhere Accept 'Configuration found in Mozilla ISPDB' opens yahoo! login sequence enter email and yahoo account password - FAILS Account Hub window 'Choose your email type' pick 'Edit configuration' Changed Incoming server settings to: POP3 pop.mail.yahoo.com Port 993 SSL/TLS Auth method OAuth2 username = email address Test 'Outgoing server settings' 'The following settings were found by probing the given server' SMTP smtp.mail.yahoo.com Port 465 SSL/TLS OAuth2 Continue Authentication error 'Unable to log in at server. Probably wrong configuration, username or password.' followed guidance from Mozilla article: https://support.mozilla.org/en-US/kb/thunderbird-and-yahoo Exit Thunderbird Wait a few moments for background process to complete Start Thunderbird counted to 10+ restarted Thunderbird Yahoo account is not there Googlemail account is there - OK 'Set up another account' - email started again Name & email opens yahoo! login sequence enter email and yahoo account password - FAILS: 'Something went wrong' - not helpful 'Go to help' in Yahoo dialog opens another page in kanji(?) close this back in TB Account Hub window 'Choose your email type' pick 'Edit configuration' Changed Incoming server settings to: POP3 pop.mail.yahoo.com Port 993 SSL/TLS Auth method Normal password [changed] username = email address Test 'Outgoing server settings' 'The following settings were found by probing the given server' SMTP smtp.mail.yahoo.com Port 465 SSL/TLS Auth method Normal password [changed] Continue 'Creating account' 'Authentication error' as before Go to https://help.yahoo.com/kb/sln27791.html Login to yahoo account 'Ways to securely access Yahoo Mail' Use an app password ************ Signed out of a 'current sessions' even if not recognised. (Except 'current device' which is the login just past. External connections-> Create app password App name : Thunderbird Generate Copied to clipboard ******************** Returned to TB entered password 'Continue' Spinning icon and re-opens yahoo login dialog entered normal password 'Something went wrong' entered app password 'Something went wrong' Despite this, after closing the yahoo dialog, TB says 'Account created successfully'!!!! Inbox appears Note:server settings now set somehow to IMAP / normal password Testing outgoing: Message fails, Yahoo dialog login fails Edit outgoing server which remains OAuth2 Changed to normal password Tried app password - failed Tried normal Yahoo password - failed

 Port 993, SSL/TLS, Normal password, username = email address

 Port 465, SSL/TLS, Normal password, username = email address