Recaptcha
This is a third-party reCAPTCHA system provided by Google. It displays a check box that your visitor must check to verify they are a human.
You need to have the correct code on your form page to display the reCAPTCHA. We have Sample Form Code that is ready to use with this reCAPTCHA. The beauty of this reCAPTCHA is that it will work on a static HTML page, as well as a "dynamic" page.
User panel -> my forms -> edit configuration
Enter the domain that your form is on. Do not include http:// or https://. It should just be your domain. This is required for Google reCAPTCHA to work.