Trying to send emails with user-input through the php mail function, but cant get it to work

Question

This is my first time learning php, and I wanted to create a simple newsletter, that would take the user's email as input and proceed to send a mail to that particular email, using the php mail() function without being redirected to another website, But I cant seem to get it to work.

<section id="subscribe">
   <div class="container wow fadeInLeft">
   <div class="subscribe text-center">
   <p>Sign Up To Our Newsletter Now</p>
   <div class="input-group">
     <input type="email" class="form-control" name="uemail" placeholder="Enter Email ID">
     <div class="input-group-append">
       <button type="submit" name="submit" class="input-group-text btn">Subscribe</button>
       </div>
     </div>
   </div>
 </div>

 <?php
 if (isset($_POST["submit"]))

 {
   $email_to = $_POST["uemail"];
   $subject = "simple emails with php";
   $message =" Testing if this is working \n\n boop bop!";
   $headers = "From: testingaux@gmail.com";
   if(mail($email_to, $subject, $message, $headers) )
       echo "success, email sent to $email_to" ;
   else
       echo 'not sent';
 }
?>


 </section>

Any help would be much appreciated. Thank You!