I'm trying to send a message to the email a user provides in the contact form. The problem is the message never gets sent, but I always arrive at a blank page where my php code is located. Nothing warns me of any error in my code. Can anyone explain why this is happening and offer a solution to the problem?
      <form action="site.php" method="POST">
      <input
        type="text"
        class="form"
        name="email"
        placeholder="Your email address"
      />
      <button class="submit" type="submit">Join Waitlist</button>
    </form>
<?php
if (isset($_POST["submit"]))
{
    $mailTo = $_POST["email"];
    $mailFrom = "Dumele";
    $message = "https://docs.google.com/forms/d/1lpj2XnKW4HT_qHFfGwpUxcvzPmK2USZ0MGSDP0XCqfg/edit";
    $subject = "Welcome to Dumele";
    
    $txt = "Thank you for your interest in Dumele. We're glad to have 
    you join our network and mission to enhance the technological 
    innovation of our African diaspora. Below is a link to a survey 
    we would like you to answer so we can better assist you.\n\n".message;
    $headers = "From: ".mailFrom;
        (mail($mailTo, $subject, $txt, $headers));
        header("Location: index.php?mailsend");
    
}   
?>
 
     
     
    