No longer getting submissions via email

I stopped getting form submission via email. These do not go to spam, they simply don't arrive.

Hello,

I found your email address in our bounce list due to the rejection of your mail server from receiving the email from JotForm. Here is the bounce back reply error from your mail server: 

Reason(s) : smtp; 550-5.7.1 Unauthenticated email from ymail.com

I suspect that this is a temporary glitch. So I have simply removed your email from the bounce list in order for the system to start sending emails again to your email address. You can test to make a submission on your form to see if you are now receiving the email alerts. You may also check your email activity history to check the status of the delivery of your email alerts by following this guide: https://www.jotform.com/help/293-How-to-View-All-Your-Form-Email-History 

If you have questions, please let us know.

Thanks.