title: Email tracking tools, How it works?
body: <p>Did you work with email tracking tools like "GetNotify.com"?</p>
  
  <p>I want to know how it works, with details.</p>
  
  <p>In my opinion we have to create a php code that contains img tag, but I don't know how can I attach this on email content.</p>
  
  <p>Thanks.</p>