[fencepost]

As in signed up for AT&T service? If so it's because it's not spam - it's misdirected mail, but there are tens of thousands of other Gmail users who think that messages almost identical to those are things they absolutely want to receive.

[RandomBacon]

If there is no business relationship between AT&T and that user, the U.S. Can Spam Act defines it as spam.

Shame on AT&T for not validating their customer's email address.

I too get the same type of spam from AT&T.

[fencepost]

My point is that absent information that Google simply does not have no matter how creepy they get, there's literally no way they can identify such messages as spam - exactly the opposite in fact because probably 99.999% of such messages that they process are explicitly not spam.

The only way Google would have to identify that this message was not for you would be to get the subscriber information from AT&T and cross-reference it with name and address information they had for you - and even then most of the time they'd probably be wrong (e.g. if the email is coming to you but the account is actually in a family member's name).