Is pop mail gone for free email users of the att.net address though yahoo?

Let's move this thread to the new Email forum.

No, you can still do POP3 email for AT&T addresses.  But chances are your email client doesn't support OAuth2, the authentication process that Yahoo now uses.  Instead you'll need to create a Secure Mail Key and use that instead of the password in your email client.  The password still works for using a browser to access your email through the web UI.

Here is a link on how to create a Secure Mail Key

That works. Thanks