Protect your web form from spam

According to wikipedia Spam is the abuse of electronic messaging systems.
Online web forms, if not protected, may be submitted many times and flooding you with unwanted information and emails.
The spam protect option forces the form filler to fill in a certain string according to a captcha image, thus ensuring that the data is not entered by a computer.
Only after the form filler enters the right captcha number the email form may be submitted.
Steps to add a “spam protect” option to your form:
1- Enter your form in the form builder
2- Go to the “form settings” on the right
3- Turn on the “spam protect” checkbox
4- Press on “apply”
5- Save the form.