title: Mass email tracking
body: <p>Most services offered online today that claim to "track" e-mails, do so by embedding images in the emails. My questions are:</p>
  
  <ol>
  <li>Is this the only way to do it and if not, what are the other methods?</li>
  <li>Are any of the methods actually fool-proof?</li>
  <li>Has anybody had any luck with specific software or even an online group?</li>
  </ol>