复选框提交相同的值独立的方框已选中或取消选中

my problem is that my e-mail form has a check box and it does not matter if the box is checked or not, it always transmits the same value, all other fields work ok, its just the checkbox I'm having problems. I tried several suggestions from this forum without luck, I'm not sure what I'm doing wrong! I'm not too proficient in PHP.

<form method="post" action="contact-form-handler1.php">
   <div class= "form">
     <div class="input-group margin-bottom-sm">
       <span class="input-group-addon">
         <i class="fa fa-user fa-fw" style="color:grey"></i>
     </span>
<input class="form-control" type="text" name="name" placeholder="Name" 
required>
    </div><br>
<div class="input-group margin-bottom-sm">
   <span class="input-group-addon">
      <i class="fa fa-envelope-o fa-fw" style="color:grey"></i>
    </span>
<input class="form-control" type="text" name="email" placeholder="Email 
address" required>
    </div><br>
<div class="input-group margin-bottom-sm">
   <span class="input-group-addon">
      <i class="fa fa-phone fa-fw" style="color:grey"></i>
   </span>
<input class="form-control" type="text" name="phone" placeholder="Phone">
   </div><br>
</div>
<div class="input-group margin-bottom-sm">
   <span class="input-group-addon">
     <i class="fa fa-comment-o fa-fw" style="color:grey">
   </i></span>
<textarea class="form-control" rows="6" type= "text" name="message" 
placeholder="Your Message" required></textarea>
   </div><br>
<div class="input-group margin-bottom-sm">
   <input class="form" type="hidden"  name="check" value="0">
      <input class="form" type="checkbox"  name="check" value="1"><span 
   </div>
   <br><br>
<div class="input-group margin-bottom-sm"><span class="input-group-addon">
   <i class="fa fa-lock fa-fw" style="color:grey"></i>
   </span>
<input class="form-control" type="text" name="code" placeholder="For 
security, please type SECURE in this field">
   </div><br>
<input class="btn btn-primary send" type="submit" value="Send Message">
</form>

<?php 
$errors = '';
$myemail = 'info@xyz.com';//<-----Put Your email address here.
if(empty($_POST['name'])  || 
empty($_POST['email']) ||
empty($_POST['phone']) || 
empty($_POST['message']))
{
$errors .= "
 Error: all fields are required";
}

$name = $_POST['name'];
$phone = $_POST['phone']; 
$email_address = $_POST['email']; 
$message = $_POST['message'];
$check = $_POST['check']; 

// if data is posted, set value to 1, else to 0
$check = isset($_POST['check']) ? 1 : 0;
if (!preg_match(
"/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/i", 
$email_address))
{
$errors .= "
 Error: Invalid email address";
}
if (strtolower($_POST['code']) != 'SECURE') {die('Wrong access code');
}

if( empty($errors))
{
$to = $myemail; 
$email_subject = "Contact form submission: $name";
$email_body = "You have received a new message from the
Mail Handler. ".
" Here are the details:
 Name: $name 
 Phone: $phone 
 Email: 
$email_address 
 Message: 
 $message 
 Signup: $check"; 

$headers = "From: $myemail
"; 
$headers .= "Reply-To: $email_address";

mail($to,$email_subject,$email_body,$headers);
//redirect to the 'thank you' page
header('Location: contact-form-thank-you.php');
} 

?>