Submission Emails Notifications Stopped Sending.

I've stopped receiving my submissions - I even changed email addresses to see if that would help, but they are no longer coming through. What is the problem?

Upon checking email logs, which you also can check following this guide, I've found that the last received submission with ID 4688412898114159182 has triggered your form email notification as shown below:

Are you sure the email is not in your email spam folder?