I have a Yahoo Plus account which downloads by POP to Thunderbird. Since 23 February, the emails have not been downloading and I cannot send messages from Thunderbird either. When I try to download my messages I get this: "Sending of password for user sihambortcosh did not succeed. Mail server plus.pop.mail.yahoo.com responded: Server error - Please try again later." Yahoo say that it is due to a change in their authentication. I am using Thunderbird version 78. The Thunderbird support page about this says this: https://support.mozilla.org/en-US/kb/thunderbird-and-yahoo. However, when I come to change the authentication method, the OAuth2 option is available only for the incoming server, but it is not available as setting for the outgoing smtp server. When I change to OAuth2 for the incoming server only (OAUth2 on the smtp server not being available) I get a message that the authentication method has not worked. Please help!