envia.php

<?php
include ('recaptchalib.php');

$to = 'alanzvinicius@gmail.com';
$subject = $_REQUEST['name'];
$email   = $_REQUEST["email"];
$message = $_REQUEST['comments'] ;


$header = "from:$email\n"; 
$header.= "MIME-Version: 1.0\r\n"; 
$header.= "Content-Type: text/plain; charset=utf-8\r\n"; 
$header.= "X-Priority: 1\r\n"; 
// sua chave secreta
$secret = "6LcZlxwUAAAAANn6mg8RK-tB1fl3ozGwAlxuO2hd";
 
// verifique a chave secreta
$reCaptcha = new ReCaptcha($secret);

// resposta vazia
$response = null;
if ($_POST["g-recaptcha-response"]) {
$response = $reCaptcha->verifyResponse(
        $_SERVER["REMOTE_ADDR"],
        $_POST["g-recaptcha-response"]
    );
}



if ($response != null && $response->success){
    $envioEmail = mail($to,$subject,$message,$header);
    if ($envioEmail){
       echo  "<script> alert(' Menssagem enviada com sucesso!'); window.history.go(-1); </SCRIPT>\n";
    }
    else
    {
		echo "<script> alert(' Error ao enviar menssagem!'); window.history.go(-1); </SCRIPT>\n";
    }
}
else {
	echo "<script> alert(' Verifique o captcha!'); window.history.go(-1); </SCRIPT>\n";
}
?>