I just noticed today that the AT&T SpamGuard on my Yahoo Mail is getting the Spam Emails even though Its set to Off, I normally have Thunderbird handle all the Emails and Spam.
This is very weird, I dont know why the SpamGuard is on when I have it set to Off on the Mail Options.
Looks like I was able to fix it. in the Mail Settings for POP & Forwarding I had to set the Allow your att.net Mail to be POPed to include spam messages.
And that seems to have fixed it. I use Thunderbird to handle all of the emails including the Spam.