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.
Sorry but we do not have popup thank you page option. You can, however, redirect to another page if you want http://www.jotform.com/help/38-How-to-Redirect-to-a-Page-After-Form-Submission.
Regarding on the thank you message sent through email, simply create an autoresponder notification on your form. http://www.jotform.com/help/26-Creating-a-Form-Autoresponder. This will be instantly sent to the user who submits the form.