title: How to include a call to a file in PHP mail() function
body: <p>I have the following function for sending an email:</p>
  
  <pre><code>function send_email($email){
          $subject = "TITLE";
  
          $message = "HERE IS THE MESSAGE";
  
          // Always set content-type when sending HTML email
          $headers = "MIME-Version: 1.0" . "\r\n";
          $headers .= "Content-type:text/html;charset=UTF-8" . "\r\n";
  
          // More headers
          $headers .= 'From: &lt;emaily&gt;' . "\r\n";
  
          mail($email,$subject,$message,$headers);
      }
  </code></pre>
  
  <p>Instead of <code>$message</code> being a string, I want to call in the file <code>email.html</code> which holds my template.</p>
  
  <p>I have added this:</p>
  
  <pre><code>require 'email.html';
  </code></pre>
  
  <p>But how can I call in the file? </p>
  
  <p>$message = [call in email.html here]</p>