How to set up a feedback form on the php to the letters you do not end up in spam?

Question

It seems all you need is there, but the messages are still not sent. Most likely, they do not reach because of the anti-spam.

How can I fix the problem?

<form method="post" action="index.php">
            <strong>Your name:</strong><br />
            <input maxlength="30" type="text" name="name" />
            <br />
            <strong>Your Email for response:</strong><br />
            <input maxlength="30" type="text" name="email" />
            <br />
            <strong>Yuur massage</strong><br />
            <textarea rows="7" cols="50" name="mess"></textarea>
            <p>
            <input type="submit" value="Send"/>
            </p>
            </form>



       <?php
    if (isset($_POST['name'])) {$name = $_POST['name'];}
    if (isset($_POST['email'])) {$email = $_POST['email'];}
    if (isset($_POST['mess'])) {$mess = $_POST['mess'];}

    $to = "engenes511@gmail.com"; 
    $headers = "Content-type: text/plain; charset=windows-1251\r\nFrom: <e9228098808@yandex.ru>";
    $subject = "Message from your site";
    $message = "Sender name: $name \nE-mail: $email \nMassage: $mess";
    $send = mail ($to, $subject, $message, $headers);
    if ($send == 'true')
    {
    echo "<b>Thank you for sending your message!<p>";
    echo "<a href='feedback.html'>Click to return</a>";
    }
    else 
    {
    echo "<p><b>Error. Message not sent!";
    }
    ?>