Есть форма, есть скрипт на пхп, хочу ее оживить с помощью него, но что-то не хочет, что не так?

<?php
if(isset($_POST['contact_form'])){
$name = htmlspecialchars($_POST["name"]);
$email = htmlspecialchars($_POST['email']);
$message = htmlspecialchars($_POST['message']);
$to = htmlspecialchars("blabla@mail.ru");
$subject = "New Contact Message " . $email;
mail($to, $subject, $message, "From: " . $name);
}else{
echo "Сообщение не отправлено";
}
 
?>
<form method="POST" action="form_process.php" name="contact_form">
 <div class="alert alert-success" style="display: none;" id="email_sent">
 <a href="#" class="close" data-dismiss="alert" aria-label="close">&times;</a>
<strong>Success!</strong> Your email has been sent successfully.
</div>
 <div class="input">
<label>Your name:</label>
 <input type="text" name="name" required></div>
 <div class="input">
 <label>Your email:</label>
 <input type="email" name="email" required></div>
<label>Message:</label>
<textarea rows="6" name="message" required></textarea>
<button type="submit" class="theme-button" value="Submit" name="submit" id="submit">Submit</button>

$name = htmlspecialchars($_POST['name']);
$email = htmlspecialchars($_POST['email']);
$message = htmlspecialchars($_POST['message']);
$to = htmlspecialchars("blabla@mail.ru");
$subject = "New Contact Message " . $email;
mail($to, $subject, $message, "From: " . $name);
 
 
?>
<form method="POST" action="email.php" name="contact_form">
 <div class="input">
 <label>Your name:</label>
 <input type="text" name="name" required></div>
 <div class="input">
 <label>Your email:</label>
 <input type="email" name="email" required></div>
 <label>Message:</label>
 <textarea rows="6" name="message" required></textarea>
 <button type="submit">Submit</button>

<?php
if(isset($_POST['name']) && isset($_POST['email']) && isset($_POST['message'])){
$name = htmlspecialchars($_POST['name']);
$email = htmlspecialchars($_POST['email']);
$message = htmlspecialchars($_POST['message']);
$to = htmlspecialchars("blabla@mail.ru");
$subject = "New Contact Message " . $email;
mail($to, $subject, $message, "From: " . $name);
}else{
echo "Сообщение не отправлено";
}
 
?>
<form method="POST" action="email.php" name="contact_form">
<div class="input">
<label>Your name:</label>
<input type="text" name="name" required></div>
<div class="input">
<label>Your email:</label>
<input type="email" name="email" required></div>
<label>Message:</label>
<textarea rows="6" name="message" required></textarea>
<button type="submit">Submit</button>

<?php
$to = 'dddd@mail.ru';
$name = strip_tags(trim($_POST['name']));
$email = strip_tags(trim($_POST['email']));
$mesage = strip_tags(trim($_POST['message']));
if(!empty($name) && !empty($email) && !empty($mesage)) {
    $subject = "Обратная форма.";
    $message = 'Имя: <b>'.$name.'</b><br>
                E-mail: <b>'.$email.'</b><br>
                Текст: <b>'.$mesage.'</b>';
    $headers = "MIME-Version: 1.0\r\n";
    $headers .= "Content-type: text/html; charset=utf-8\r\n";
    $headers .= "From: VASH SAIT <".$to.">\r\n";
    if(mail($to, $subject, $message, $headers)) {
        echo'Ваша сообщение успешно отправленщ!';
    } else { echo 'При отправке сообщения возникла ошибка!'; }
} else {
    echo 'Заполните все поля!';
}
?>
<form method="POST" action="email.php" name="contact_form">
<div class="input">
 <label>Your name:</label>
<input type="text" name="name" required></div>
<div class="input">
 <label>Your email:</label>
<input type="email" name="email" required></div>
<label>Message:</label>
 <textarea rows="6" name="message" required></textarea>
 <button type="submit">Submit</button>

<?php
$to = strip_tags(trim($_POST['address']));
$name = strip_tags(trim($_POST['name']));
$email = strip_tags(trim($_POST['email']));
$mesage = strip_tags(trim($_POST['message']));
if(!empty($name) && !empty($email) && !empty($mesage)) {
    $subject = "Обратная форма.";
    $message = 'Имя: <b>'.$name.'</b><br>
                E-mail: <b>'.$email.'</b><br>
                Текст: <b>'.$mesage.'</b>';
    $headers = "MIME-Version: 1.0\r\n";
    $headers .= "Content-type: text/html; charset=utf-8\r\n";
    $headers .= "From: VASH SAIT <".$to.">\r\n";
    if(mail($to, $subject, $message, $headers)) {
        echo'Ваша сообщение успешно отправленщ!';
    } else { echo 'При отправке сообщения возникла ошибка!'; }
} else {
    echo 'Заполните все поля!';
}
 
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
   <form method="POST" action="email.php" name="contact_form">
 <div class="input">
 <label>Your name:</label>
 <input type="text" name="name" required></div>
 <div class="input">
 <label>From email:</label>
 <input type="email" name="email" required></div>
 <div class="input">
 <label>To email:</label>
 <input type="email" name="address" required></div>
 <label>Message:</label>
 <textarea rows="6" name="message" required></textarea>
 <button type="submit">Submit</button>
 </form>
</body>
</html>