Thunderbird server does not support selected authentication method
Thunderbird says "server does not support the selected authentication method." Server is AT&T. I saw that changing server setting to OAuth2 helped, but I can only change in bound server setting to OAuth2. Drop down list for authentication method for outbound server does not contain "OAuth2" - only options are Normal Password, Encrypted password, NTLM, or Kerberos/GSSAPI. HELP!
Opaite Mbohovái (2)
Use the correct server settings given here:
https://www.att.com/support/article/dsl-high-speed/KM1010523/
Use 'normal password' authentication but enter a secure mail key instead of the account password:
more info here.
for "att.net" based email mail-servers, first get a (secure mail key) SMK code from att web mail access website , use the code as password in the TB's att mail-account (it should use "Normal Password" auth-method & SSL/TLS security as shown in the link) , before adding code as password, you should remove earlier password from "Saved Passwords" in TB , restart TB.
above is sufficient, but if you want to use OAuth, then enable Cookie in TB & change authentication method (auth-method) from "Normal Password" into "OAuth2", click on Sent/Inbox, etc folder, and follow the OAuth verification process . restart TB.