Don’t be fooled by this phishing attempt to get your AT&T account details (or worse). In the example below you will see that the “log in” link does not point to AT&T‘s website. A VirusTotal scan of the URL revealed that the target site is “malicious”. Do not click on links or download attachments that may accompany this fake AT&T email. Flag the email as spam and delete right away!
If you have a genuine reason to be concerned about your bill you should visit AT&T’s website directly or call call their customer support department. See also AT&T’s website on phishing scams and how to protect yourself.