Source of: /ADI/email/contact_action_.php

<?php

  $secret = "6LeIxAcTAAAAAGG-vFI1TnRWxMZNFuojJ4WifJWe";
  
  $name  = $_POST[name];
  $email    = $_POST[email];
  $message    = $_POST[message];
  $captcha = $_POST[captcha];

  //Verifying the user's response

  
  
   $url = 'https://www.google.com/recaptcha/api/siteverify';
   $data = array('secret' => $secret, 'response' => $captcha);
       $options = array(
           'http' => array(
           'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
           'method'  => 'POST',
           'content' => http_build_query($data),
       )
   );

$context  = stream_context_create($options);
$response = file_get_contents($url, false, $context);


   $json = json_decode($response, true);
  

 
 if ($json['success']) { 
 
  // Send a confirmation message to the person.
  $message = "Hello $name

We have received your message:

$message

Thank you for your contact,
you shall hear from us shortly!

- Figo
";

  mail($email,"Your contact",
       $message, "From:Figo <figo@deei.fct.ualg.pt>");
 
  $report="Dear $name, Thank you for your contact!";
  include('message_template.html');

} else {
   // Your code here to handle a failed verification
   $report="Whoops, message failed, try again.";
   include('message_template.html');
  }
 
?>