This wouldn’t be a billing issue, so much as potentially an app bug or something that changed in our invoicing process. You’ve definitely been billed, and billed the right amount all this time, correct?
I’ve been trying to find any changes we made about a year ago that might have resulted in the notification being deactivated, but I’m not finding anything.
If you do open a ticket about the missing notifications, please do not allow yourself to be talked into factory resetting the phone as a final troubleshooting step. The matter needs to be investigated as a possible bug, not as something specific to your phone.
Also, when an e-mail address is rejected by the e-mail provider, we stop sending to that address. I can ask to have the internal block removed to so we can see if your original e-mail address can once again receive our e-mails, if you’d prefer that over using a different e-mail address.