paypal invalid ipn

[eluser]ray73864[/eluser]
ipn is called as soon as the person presses the 'pay now' button i believe, basically ipn is for validating the data instead of requiring a ssl connection, so the person clicks 'pay now' on paypal, paypal sends all the data to your server's ipn function, the ipn function packages it all up and sends it back to paypal exactly as it received it, if paypal receives it back correctly then it is assumed to be coming from your server.

if i remember correctly though, i believe the ipn stage can happen at any time after they press the paynow button, it will be whenever the paypal server has a free moment to do it.