OAuth2 not available for att.net SMTP server

[tomdkat]

Hi! A friend has been using Thunderbird to access two SBC Global email accounts for a few years now. Today, he gets a "server error" when trying to receive email from one of the two email accounts. Both accounts use POP3 for incoming mail.

At first, I thought it was the OAuth2 changes Yahoo! has been rolling out that caused the problem. So, I guided him down the path of converting his accounts to use OAuth2. For this one particular account, OAuth2 was available as an option for the POP3 server (inbound.att.net) but it was NOT available as an option for the SMTP server (outbound.att.net).

I believe he's using Thunderbird 78 (but I'm not sure of the minor version information and I'll get that today).

For now, my question is: why would OAuth2 be available for the POP3 server (inbound.att.net) but not available for the SMTP server (outbound.att.net)?

Thanks in advance!

Peace...

[KAWill70]

Here are two threads with helpful information.

https://support.mozilla.org/en-US/questions/1309708

https://support.mozilla.org/en-US/quest ... er-1359490

[tanstaafl]

Is your problem solved?