PHP Mail code snippet

<?php

if(isset($_POST["submit"])) {
    $recipient="iamtundeyusuf@gmail.com";
    $subject= "Form to email message";
    $sender= $_POST["sender"];
    $senderEmail= $_POST["senderEmail"];
    $message= $_POST["message"];
    $adminEmail = "uxtheclass@gmail.com";

    $headers = "From: " $adminEmail . "\r\n" .
    "CC: chuckseveristus7@gmail.com";

    $mailBody="Name: ".$sender"<br>Email: ".$senderEmail."<br>".$message;

    mail($recipient, $subject, $mailBody, "From: $sender <$senderEmail>");

    $thankYou = "Thank you! Your message has been sent.";
}

?>
<!DOCTYPE html>

<html>
<head>
    <meta charset="utf-8">
    <title>Contact form to email</title>
</head>

<body>

    <?php echo $thankYou; ?>

    <form method="POST" action="<?php $_SERVER["PHP_SELF"] ?>">
        <label>Name:</label>
        <input name="sender">

        <label>Email address:</label>
        <input name="senderEmail">

        <label>Message:</label>
        <textarea rows="5" cols="20" name="message"></textarea>

        <input type="submit" name="submit">
    </form>

</body>

</html>