title: Paypal multiple IPN setup
body: <p>I am not 100% clear about this when using IPN for let's say 3 websites, and if someone with the knowledge could explain this to me according to my scenario, I will appreciate it.</p>
  
  <p>I have setup my sanbox test business account to use the IPN listener : site1.com/listener.php (Working just fine).</p>
  
  <p>I am wondering about how to setup more listeners for my other sites, using the same paypal account.</p>
  
  <p>In my scenario, I am working with <strong>only subscription payments</strong> for all sites.</p>
  
  <p><strong>Question 1:</strong>
  The <strong>ipn_notification_url</strong> variable.
  Will this variable, if set, tell paypal when the payment is made, to always use this as the listener ipn url? Example; if the subscription fail or something like that when next montly payment is made? </p>
  
  <p>So when paypal have the need to IPN my listener, it will use the listener from the variable and not the set url in account profile settings? Or will this variable ONLY be used for the actual payment when beeing processed? </p>
  
  <p><strong>Question 2:</strong>
  Is it possible to distinct the websites apart, if need to have a master listener, that handles the forwarding to the correct listener url? Example: custom = userId , receiver_id = Sitename</p>
  
  <p>Question 2 is actually similar to the question 1. Will the <strong>POSTED variables</strong> from the initial payment, <strong>STICK to the payments</strong> that are going automaticly in the future for my subscriptions. So that when paypal need to send me IPN updates, it will always use the url from my variable set on initial payment??</p>
  
  <p>Thanks for any enlightment on this.</p>