sendemail.php not working

sendemail.php file code is as follows :

<?php
    header('Content-type: application/json');
    $status = array(
        'type'=>'success',
        'message'=>'Email sent!'
    );

    $name = @trim(stripslashes($_POST['name']));
    $email = @trim(stripslashes($_POST['email']));
    $subject = @trim(stripslashes($_POST['subject']));
    $message = @trim(stripslashes($_POST['message']));

    $email_from = $email;
    $email_to = 'info@siteaddress.com';

    $body = 'Name: ' . $name . "\n\n" . 'Email: ' . $email . "\n\n" . 'Subject: ' . $subject . "\n\n" . 'Message: ' . $message;

    $success = @mail($email_to, $subject, $body, 'From: <'.$email_from.'>');

    echo json_encode($status);
    die;
?>

and the form design code is

<form id="main-contact-form" class="contact-form" name="contact-form" method="post" action="sendemail.php" role="form">
<div class="row">
<div class="col-sm-6">
<div class="form-group">
<input type="text" class="form-control" required placeholder="Name" name="name" id="name">
</div>
</div>
<div class="col-sm-6">
<div class="form-group">
<input type="text" class="form-control" required placeholder="Email address" name="email" id="email">
</div>
</div>
</div>
<div class="row">
<div class="col-sm-12">
<div class="form-group">
<textarea name="message" id="message" required class="form-control" rows="8" placeholder="Message" name="message" id="message"></textarea>
</div>
<div class="form-group">
<button type="submit" class="btn btn-danger btn-lg">Send Message</button>
</div>
</div>
</div>
</form>

mail is arriving at the address info@siteaddress.com but with blank fields .... what should be the cause..... please help