Contact Form 7 Captcha: Breakdown
Contact Form 7 Captcha is a plugin that adds a Captcha (Completely Automated Public Turing test to tell Computers and Humans Apart) field to your contact form. This Captcha field is used to verify that the user who is submitting the form is in fact a human being. It works by displaying a code in an image at the right side of the form, also known as a CAPTCHA challenge. The user must then enter the code from the image into the field in order to verify they are a human being.
With Contact Form 7 Captcha, you can customize the Captcha challenge-response system to your needs. You can set how often the Captcha challenge is displayed, how many characters the Captcha code contains, and even the colours of the Captcha fields. You can also opt to lock the form submission if the Captcha response is incorrect.
The Captcha field also works with other forms of security measures. You can set the Captcha field to either be part of a comprehensive anti-spam system or to be used as a standalone solution. In addition, Contact Form 7 Captcha includes an automatic spam filter which can detect and block potential spam messages.
The Captcha field can also be configured to block specific types of email addresses. For example, you can specify whether the Captcha should block known spam emails, emails from known malicious IP addresses, or emails from certain domains.
Finally, Contact Form 7 Captcha also comes with an optional antispam honeypot, which works to prevent automated scripts from submitting forms without any human interaction. The honeypot works by asking the user to answer a question that only a real human being would know and submit the answer along with the Captcha response.