JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
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.
Unfortunately, we don't have a "Sent" folder where you can view the replies that you made from the Submissions page.
You can check the mail logs and you'll see that once you replied to a customer, a log will be created. However, this will be difficult, because it doesn't show whether it is an email notification, reply, or autoresponder. The logs will only shows email messages coming from our servers. Here's a screenshot:
I would suggest using your email client to reply to the users rather than replying from the Submissions page.
Hope that helps. Thank you.