通过php淘汰垃圾邮件发送者/机器人

Question

I am trying to create a hidden email field in my contact form that, when filled out, will not send me an email (meaning a spammer filled in the hidden email field), instead, just sending the spammer to a confirmation page saying that the email was sent.

I can't get it to work properly.

Test site - http://www.webexplosive.com/s1/contact.html

Here is my php script for the contact form:

<?php
    $firstname = $_POST['firstname'];
    $lastname = $_POST['lastname'];
    $email1 = $_POST ['email1'];
    $phone = $_POST ['phone'];
    $comments = $_POST ['comments'];
    $testBot = $_POST ['email2'];

    $headers = "MIME-Version: 1.0
";
    $headers = "From: $email1";
    $to = '[e-mail]';
    $subject = 'Contact Form Submitted - Virginia Subsite';
    $message = "
    First name: $firstname 

    Last name: $lastname 

    Email: $email1 

    Phone: $phone 

    Comments: $comments 
";

    mail($to, $subject, $message, $headers);

    header("Location: thankyou.html");

    if(email2 == "") { //If email2 form section is blank then... 
        $firstname = $_POST['firstname'];
        $lastname = $_POST['lastname'];
        $email1 = $_POST ['email1'];
        $phone = $_POST ['phone'];
        $comments = $_POST ['comments'];
        $testBot = $_POST ['email2'];

        $headers = "MIME-Version: 1.0
";
        $headers = "From: $email1";
        $to = '[e-mail]';
        $subject = 'Contact Form Submitted - Virginia Subsite';
        $message = "
        First name: $firstname 

        Last name: $lastname 

        Email: $email1 

        Phone: $phone 

        Comments: $comments 
";

        mail($to, $subject, $message, $headers);

        header("Location: thankyou.html");
    }
    else {
        header("Location: thankyou.html");

    }
?>

Answer 1

This is because you always call the mail form first. You need to validate it before you call it. Call the mail function after you have checked that the email2 field is empty.

As it is, it will always send the mail, before hitting the if statement.

Suggestion: Look into implementing a captcha or something similar than that.