Lately I started getting emails supposedly from ATT informing me that I needed to sign into my Yahoo account (ATT piggybacks on Yahoo) or my email account would be canceled. BS says I and called ATT. After discussing my problem with the 'bot, I finally got a person on the line, confirmed BS and was told to forward said email to their abuse address.

If you get a similar email, investigate the embedded link, it does not go to Yahoo. It goes to a sign-in page on a third-party website so you can very conveniently sign in and give them all they need to have access to your account.