i don't get an email when somebody fills in my form

I have a yogaschool and use a jotform for people to apply for a lesson. But since half a year it happens a lot that i don't get a notification when somebody fills in the form. I don't always check the inbox at the jotform site, because i expect to get an email notification on my own account. But it doesn't always work, so I miss some applications which is very annoying. 

I have a few form, the application form is the mot important, because that is the one that i need to answer back if someone sends me an application. It is the link at the bottom of the page called: Voor een inschrijfformulier klik hier.

I checked if you are in the bounce list. And you are not:

Result:
emma@theex.nl is NOT in the bounce list
emma@theex.nl is IN  the unsubscribe list

This problem usually occurs when messages are rejected by your email provider. Here's how you can prevent this:

How to Prevent Email Bouncing Related Issues

Also you have to option to use your own custom SMTP server (like gmail for example) That would completely eliminate the problem of sent mail being blocked.

How to Setup SMTP for a Form