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.
You can get the user's IP address if they have successfully submitted the form. Here's how you can get it: http://www.jotform.com/help/31-How-to-See-IP-Addresses-of-Form-Submitters.
But for email address and other more specific identifiers, you cannot get them automatically, your responders need to fill out the form fields for those information. Example, your form should have an email address field.