问题
how to test with paypal ipn simulator. how to test it in localhost or live server. i am getting "IPN was not sent, and the handshake was not verified. Please review"
回答1:
The handshake error is most likely to occur when your server/keystore config is non-compliant with the upgraded PayPal SSL encryption algorithms.
IPN simulator will connect againest the PayPal Sandbox environment, which has been upgraded with Versign G5 root cert / SHA-2 encryption algorithms (btw this is an industry standard as supposed to be everywhere in 2016). Once your IPN host failed to meet the compliance, the SSL connnection will error out with handshake problems.
Please see link for more info
IPN was not sent, and the handshake was not verified. Please review your information.
来源：https://stackoverflow.com/questions/33363517/paypal-ipn-simulator-getting-error