Change the authentication to OAuth2, and that will work alongside 2SV. OAuth is currently supported in TB only for IMAP accounts with Yahoo, gmail and a few others, but support for POP is expected soon.

Thank you for your information. I'm not too sharp on this stuff, so how do I find the OAuth2 and the 2SV windows to enter this particular information. I'm currently using an existing account that I've been using for a lot of years now. I'm hoping that I can continue to use this same Thunderbird without losing my history. Can you please guide me where to click to find the entry spots for the information you furnished to me? I do appreciate your time and effort. Ralph

Open Tools/Account Settings, select Server Settings for the account in the left pane, note the Server Type. If it's POP Mail Server, the authentication method is 'normal password', and if you have 2-step verification on the account, you have to use an app password in place of the regular account password. This won't work when they require OAuth authentication, which currently isn't supported for POP in TB.

If the Server Type is IMAP, the authentication can be changed to OAuth2. Same for the outgoing server in Outgoing Server (SMTP) in the lower left pane of Account Settings. If you make the change, first delete the account passwords in Tools/Options/Security/Passwords/Saved Passwords, restart TB, and enter your regular account password in the OAuth browser window that appears at the next connection to the account.

If the account is POP but you want to change to IMAP, follow these instructions: http://kb.mozillazine.org/Convert_a_POP_account_to_a_IMAP_account

rsantasiero said

Thank you for your information. I'm not too sharp on this stuff, so how do I find the OAuth2 and the 2SV windows to enter this particular information. I'm currently using an existing account that I've been using for a lot of years now. I'm hoping that I can continue to use this same Thunderbird without losing my history. Can you please guide me where to click to find the entry spots for the information you furnished to me? I do appreciate your time and effort. Ralph

OAth for pop will appear in a few weeks as an option for POP mail accounts. It has been incorporated in the beta release and I would hope to see it in the next available point release of Thunderbird.

Although it doesn't allow for me to initiate this change right now I'm hopeful that the update information you provided is going to work out. Do you think Yahoo will advise me when this change is made to their program? Thank you for your time and efforts into helping me sove this problem. Ralph

I wouldn't count on Yahoo informing its customers of the change. More likely, they will simply withdraw the option to create app passwords, as has been done by Sky, a Yahoo-based mail service in the UK. So, if your Yahoo account is POP, with 2SV, you may still be able to generate an app password. Or, use the latest TB 73beta2 which supports OAuth for Yahoo POP. Changing to IMAP is probably a better option than installing the beta TB, as OAuth2 works with Yahoo IMAP in the release version of TB.

I think the change has come sooner than expected. For the past 2 years I have used IMAP OAuth2 with 1 step logon. Starting Feb 1, 2020, it stopped working and i get a message "Authentication failure while connecting to server imap.mail.yahoo.com" Does anyone have any suggestions on how to set 2 step authentication with Yahoo IMAP accounts?

As I understand it, if you set 2SV on the account, it doesn't affect your access to the account in TB as long as the authentication is OAuth2. If it's 'normal password', then you would have to create an app password and use that in TB. But I see that they require the Account Key, if you have one, be disabled before 2SV can be set up.

If your IMAP account with OAuth2 has stopped working, I would try and reset the OAuth token by deleting it from Options/Security/Passwords/Saved Passwords, restarting TB, and entering the regular account password when prompted in the OAuth browser window.

The suggestion worked for me. Thank you sfhowes. Yahoo now requires 2 step verification for logging on through TB. In summary, here is what I did: 1. Erased any saved passwords 2. Closed TB 3. Logon onto Yahoo mail through the web and change to 2stepverification 4. Restarted TB and TB/Yahoo will prompt you for the logon and a 2 step verification code.

Just to clarify, did you see an OAuth browser window where you entered the regular account password, and then a separate window to enter the 2SV code?

Yes. After I entered my password, I was asked how I wanted to receive the verification code. After I answered that question, a dialog box came up asking me for the code. After I entered that, the IMAP started syncing for the first time in 9 days.