sandbox not hitting notifyurl

This seems to be a common problem but I can't seem to find any solutions for it. I have used the Ipn simulator testing and it works fine, but when I test out a transation by going through the payment process Paypal never hits my Ipn Listener. I am currently testing in the sandbox

I am using the Express Checkout API and setting the NotifyUrl in the DoExpressCheckoutPayment met开发者_如何学运维hod. Why is paypal not hitting the url specified in there?

Problem was the documentation and version I were using didn't match up, so I was using deprecated parameters. For some reason using deprecated commands does not throw any errors, so it is hard to debug.

Paypal does a real good job of hiding their documentation and making it difficult to match API version with documentation version.

To take a stab, are you sure the URL is accessible by paypal? Paypal is calling it so urls like localhost will not work. If it is https and you're using a development certificate that might explain it as well. Is your firewall possibly blocking it?