Did not receive email notification for internet bill

Yesterday I checked my Cox account online to see when my bill was due. To my surprise, it was due the day before. I already set up my email for online billing, yet I did not receive an email notifying that my bill was due. Am I missing something here? I've already checked the "Paperless Billing" page on my Cox account and it even says that monthly bills will be sent to my email address. I emailed Cox support and I got the classic automated response that did not address the issue at hand. 

This is barely my second bill, if that makes a difference. What can I do to fix this?