PayPal has sent us emails a few times over the past several months informing us that we still need to update our IPNPB code to https before June. However, when I would use the IPN simulator to test our existing listener (without https), it would always return a message of "IPN was sent and the handshake was verified." This was puzzling, since my understanding was that the sandbox only accepted https postbacks. However, yesterday when I tested it, the simulator kept reporting "internal server error" even though I had made no changes to our site, so I assumed it was a paypal issue. Today, the response I always get from the IPN simulator is "IPN was not sent, and the handshake was not verified. Review your information.", regardless of whether I put my listener in test mode or live mode-- in fact, the same response occurs regardless of what IPN handler URL I put into the simulator! I would think that it should report something like "IPN was sent, but the handshake was not verified...". Is there a problem with the simulator?
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