title: Where does Paypal's ipn_email come from?
body: <p>In my PHP code for handling the IPN, everything works fine, except for one line:</p>
  
  <pre><code>$email = $_GET['ipn_email'];
  </code></pre>
  
  <p>This was in the example code they offer in order to get you started. I assumed it would retrieve the email address that was associated with the administrator of the Paypal account doing the billing.</p>
  
  <p>However, it seems to never get set. If I use the code above, my IPN script fails. The only way my IPN script works is if I simply set <code>$email</code> to some arbitrary email address of my choosing.</p>
  
  <p>Is is okay for me to just set my own email address? Should I be getting an <code>ipn_email</code> value from <code>GET</code> data? What is the value of <code>ipn_email</code> supposed to be?</p>