<sorry, ignore this reply>

Tried Yahoo account password and app one time password

With OAuth authentication you'll have to use the account password only.

Don't use a VPN while authenticating.

Also make sure not to run any software which occupies TCP port 80 on localhost, e.g. like a local web server.

It started happening to me also a few days ago.

Removed and setup a new "app" password and the default password, same "something went wrong" error but in Portuguese. Cookies enabled. No software using TCP port.

Trying to search for help on Yahoo about using IMAP on app, such as Thunderbird sent me to this page (sorry couldn't find in english)

https://br.ajuda.yahoo.com/kb/new-mail-for-desktop/SLN-sln28681.html

There is a link to accept new policy privacy but it just sends to their webmail. It says to use imap server as export.imap.mail.yahoo.com, but same error still happening.

Based on last two years, they must do something in their servers around this time of the year, because I have several e-mails about Yahoo passwords resets and new passwords created around end September and October.

With OAuth authentication you'll have to use the account password only.

Don't use a VPN while authenticating.

Also make sure not to run any software which occupies TCP port 80 on localhost, e.g. like a local web server. </blockquote>

Thank you for the information, but none of that seems to be the issue. As I mentioned earlier, I used the account password. And there is no active VPN, and no service is running on port 80. ☹️

Decided to test the config in eM Client that was installed in 2021 because of similar issue, which already had the same Yahoo account configured, I just updated the software. EM Client just asked for the new password, since the app password has changed and it downloaded my e-mail flawless.

Tried to disable firewall to test, same error.

So this might be something with the "browser" that Thunderbird is using. Enabling/disabling cookies, clearing caches, cookies and passwords saved, nothing worked so far on Thunderbird.

Still not working but I was able do advance forward.

After copying the login URL from Thunderbird and pasting it on my normal browser, I was able to go make my password accepted and Yahoo asking me to give permission for the third party app to access. After giving the permission, and I received an e-mail about a new login I get to the following URL:

http://localhost/?code=[random characters]

Since you cannot paster URL on Thunderbird internal browser, I got stuck again. Also after a few tries not even the Yahoo login screen shows up, just a message:

Edge: Too Many requests

I don't even use Edge as my browser, so I don't know why Thunderbird gets stuck before the permission page.

I used the account password. And there is no active VPN, and no service is running on port 80.

What version of Thunderbird are you running?

Try to clear any cookies which may have been set in Thunderbird by now.

Then start Windows 10 in safe mode with networking enabled. Does the problem go away?

Only for a few minutes but it temporary worked

In Account Settings->Server Settings Changing the "Authentication Method" back to "Normal" Use app password when prompted

This worked for around 10 minutes, received all my e-mails, then showed a popup with wrong password and back again to Yahoo popup and not working again.

Having the same issue but changing the authentication method to normal is working for now.

Same situation here, just started recently. The pop-up window that is displayed when attempting to get messages is titled Enter credentials for email_address@yahoo.com on imap.mail.yahoo.com with a long URL to https:/login.yahoo.com, followed by the error "Edge: Too Many Requests". Connecting to the account using webmail via Firefox works fine. Was running v128.14.0esr, upgraded to 140.4.0esr to no avail. Clearing startup cache didn't help. I have two other working Thunderbird connections to Yahoo email accounts; this problem only affects the third account , which was working until recently. Have tried lowering the Advanced Account Settings: Maximum number of server connections to cache on my two working accounts, but it didn't help. Am hesitant to disconnect one of the working accounts to test if the problematic account would then work, in the event that I would be left with only one working account connection. Am on Win10 with Extended Security Updates enabled, but am seeing similar error reports from Win11 users, as well as from users attempting to connect via browsers other than MS Edge. Common thread in the reports might be Chromium and Yahoo?

First, generate an app PW - see https://help.yahoo.com/kb/SLN15241.html.

Then go to TB menu > Settings > Privacy & Security > Passwords:

- click the 'Saved Passwords' button and edit the Yahoo entry to add your new app PW

Next, go to TB menu > Account Settings > Server Settings and set the following:

- Server Name: export.imap.mail.yahoo.com - Port: 993 - Connection Security: SSL/TLS - Authentication method: Normal password

On the left column, scroll down and click 'Outgoing Server' and edit the Yahoo entry:

- Server Name: smtp.mail.yahoo.com - Port: 465 or 587 - Connection Security: SSL/TLS - Authentication method: Normal password

After that's done, try logging in.

BTW, this fix is mentioned in the related [bug](https://bugzilla.mozilla.org/show_bug.cgi?id=1997062).

Did you exceed your quota on the Yahoo server?

To clarify the above statement: Quota here is meant as OAuth capacity for Thunderbird, not space capacity. "OAuth capacity" in the context of authentication failures, like those with Yahoo email and Thunderbird, generally refers to the maximum processing limit a service (like Yahoo's authorization server) has for handling OAuth-related requests within a given timeframe.

OAuth is the standard that allows an application (like Thunderbird or a web browser's mail client) to access a user's data (like their email) on a service (like Yahoo Mail) without requiring the user to share their actual password with the application. Instead, it uses temporary Access Tokens.

The authentication process involves the client app and the user going through a multi-step flow with the service's Authorization Server to get these tokens. This process is resource-intensive for the server.

In short, "OAuth capacity" is a bottleneck metric—when it's reached, even valid requests can fail due to temporary server overload. In other words, the problem is possibly some sort of overload situation on the Yahoo authorization server.

A possible workaround can be generating an App Password for Thunderbird. See https://help.yahoo.com/kb/SLN15241.html

Then change the Authentication method to "Normal password" in the Thunderbird server settings for the Yahoo account, and use the generated app password to login when prompted.