问题
I am trying to get my PayPal IPN Listener to work on my Live environment, it works on Staging perfectly and the issue is something to do with the web.config file:
(http://pastebin.com/B8YhJEZK)
I am using "https://developer.paypal.com/us/cgi-bin/devscr" and the Instant Payment Notification (IPN) simulator to test the web service however I am getting the following:
"IPN delivery failed. HTTP error code 500: Internal Server Error"
回答1:
You might want to read this announcment from PayPal in regards to some changes they made to their Instant Notification Service (ipn).
enter link description here
also, check your code and see if you have something similar to this:
$fp = fsockopen($host,"80",$err_num,$err_str,30);
And try changing it to something like this:
$fp = fsockopen('ssl://'.$host,"443",$err_num,$err_str,30);
来源：https://stackoverflow.com/questions/10295435/web-config-paypal-ipn-listener-http-error-code-500-internal-server-error