Email notifications not coming through

For several months the Notification 1 email on my only form was working properly and I was receiving email notice whenever someone submitted. The most recent customer submitted a form on 1/26 that was never delivered to my inbox. Since then, I've submitted 5 tests and have deduced that the only way to get a notification to be delivered to my inbox is to add a second email address to the notification list. I prefer to not have to do this. I wonder if this bug is due to the update you just released. Please help :)

I have checked the email history log of the account registered email address and see that your recent test submission is sent successfully from our end.

Did you change the recipient email address in the notification since there are no email notifications sent to this address recently before your test submissions? If so, please check if the email address is in the bounce list and you can remove it by following the guide How-to-Remove-Your-Email-Address-from-Bounce-List. Also, please check the following guide that can help you with troubleshooting email delivery issues.

http://www.jotform.com/help/208-How-to-setup-email-alerts-to-prevent-email-bouncing-related-issues 

Please get back to us if the issue still persists. We will be happy to assist you further.