I have a problem for testing Paypal with the "IPN Simulator". When I enter the url "http://localhost:3000/commande/notify_paypal" I have the error "IPN delivery failed. Unable to connect to the specified URL. It's the same think in my application, IPN doesn't work. Please verify the URL and try again.". Of course, this is a valid URL. I think it's caused by the port number. I tried to install passenger to resolve that but passenger doesn't work.
Have you a solution?