Why is my contact form PHP script not working? No error log

I don't get any errors. I used to get Undefined index/variable errors before but I fixed that with isset(). I fill the form out and hit submit but nothing shows up but a blank white screen.

This is my PHP code:

    <?php 


    $name = isset($_POST['name']) ? $_POST['name'] : '';
    $email = isset($_POST['email']) ? $_POST['email'] : '';
    $message = isset($_POST['message']) ? $_POST['message'] : '';   
    $from = 'From: ContactForm'; 
    $to = 'email@email.com'; 
    $subject = 'Hello';
    $verify = $_POST['verify'];

    $body = "From: $name\n E-Mail: $email\n Message:\n $message";

    if (isset($_POST["submit"]) && $verify == '4') {
        if (mail ($name, $email, $message)) { 
            echo '<p>Your message has been sent!</p>';
         } 

        else { 
            echo '<p>Something went wrong, go back and try again!</p>'; 
         }
      }    
        else if (isset($_POST["submit"]) && verify != '4') {
            echo '<p>You answered the anti-spam question incorrectly!</p>';
         }

?>

This is my HTML code:

          <form action="pages/mail.php" method="post">

                        <div class="col-md-12">
                            <div class="form-group">
                                <label for="name" class="sr-only">Name</label>
                                <input placeholder="Name" id="name" type="text" class="form-control input-lg">
                            </div>  
                        </div>

                        <div class="col-md-12">
                            <div class="form-group">
                                <label for="email" class="sr-only">Email</label>
                                <input placeholder="Email" id="email" type="text" class="form-control input-lg">
                            </div>  
                        </div>

                        <div class="col-md-12">
                            <div class="form-group">
                                <label for="message" class="sr-only">Message</label>
                                <textarea placeholder="Message" id="message" class="form-control input-lg" rows="3"></textarea>
                            </div>  
                        </div>

                        <div class="col-md-12">
                            <div class="form-group">
                                <input id="submit" type="submit" class="btn btn-primary btn-lg " value="Send">
                            </div>  
                        </div>

                        <div class="col-md-12">
                            <div class="form-group">
                            <label for="verify" class="sr-only">Verify</label>
                            <input name="verify" placeholder="What is 2+2" class="form-control input-lg">
                            </div>
                        </div>
                    </form>