Users are not receiving an email confirmation when they submit the form

Some of our customers are not receiving a PayPal e-receipt after purchasing our product via our JotForm: https://form.jotform.com/53347367741158

Is there a setting we need to adjust in either JotForm or Paypal to fix this issue?
Thank you -
Kris  

I checked your form and there is not currently an email autoresponder set up.  Add an autoresponder email and set the recipient address to the email field in your form:

https://www.jotform.com/help/26-Setting-up-an-Autoresponder-Email

Once that is added, the users filling out the form will receive an email confirmation when they fill out the form.