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.
Kindly ask the email recipients to check their SPAM folder if the mail was flagged accidentally.
Additionally kindly ask the users to create free jotform accounts with the email addresses they will then be able to access the shared forms.
I don't know about sub-users must have account too.