Looking at the notice in the link it appears they're trying to tell you that the email address it not associated with a Cox Internet subscriber. That being the case, they would have no way to know what address to mail a notice to so they have to resort to emailing it hoping that whomever is using the email account will see it and reach out for assistance. There's a variety of reasons an email address can become orphaned like this but it sounds like they're in the process of removing orphaned email accounts that go unclaimed. If you want to keep this email account I recommend reaching out so that the issue of linking it back to an active Cox subscriber can be resolved.
I dont understand how its not tied to his account. He's had service far longer than I. I'll talk to him next week and see what we can do.
