Form-to-mail probe prevention with Captcha and JS form validation
If you are experiencing bogus data being submitted through your form-to-mail, it could be a result of a spammer who is ‘probing’ the form-to-mail script on your website to determine whether it is vulnerable to abuse.
If your form-to-email script is publicly accessible, there is unfortunately very little that can be done to prevent these probes. The web server hosting your site cannot distinguish between the spam probes and legitimate form submission. Once the spammer realizes that your form-to-mail script is not vulnerable, they will move on and the mail you receive from these probes should cease.
The form-to-mail options provided by xneelo are secure.
One way to reduce probing of your forms is a solution that has been developed by the CAPTCHA Project. The CAPTCHATM is a program that can generate and grade tests (images of text/numbers) that most humans will read/pass and most current computer programs will fail. For example, humans can read distorted text, but current computer programs can’t.
For implementation and examples code, please refer to the following URL:
ReCaptcha Developer’s Guide