What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
I have checked your email history and found emails are sending without any problem, you can also check your email history by following this guide: How-to-View-All-Your-Form-Email-History
Also, here's a guide that will help you to know why emails may not be sending: Why-I-am-not-Receiving-Email-Notifications
I would also suggest you to check your spam and junk folders, may be that email notifications ended up there, if you find them, removing emails from this list will help you to receive future emails in your inbox folder.
You could also set up a custom sender email address to avoid problem with emails since this will use your own mail server info: How-to-Setup-SMTP-for-a-Form
Hope this helps.