How To Verify Email For a Zoho Form?

How To Verify Email For a Zoho Form?

I have a Zoho form on my website which allows people to complete the form to register for an upcoming event. They complete the fields and then submit it. I receive an Email with all the fields completed. 
Recently, I had a person submit a FAKE registration form. 
How can I verify the identity of the person who submitted the FAKE registration form sent through Zoho?