We are having a problem with IPN Notifications. We are receiving the PayPal Instant Payment Notification Warning emails when we receive a payment outside of our online store. The IPN URL works fine for store purchase, but fails when someone pays using a PayPal generated invoice. This makes sense, of course, because the store URL is not expecting a callback and refuses it when it comes from an invoice. Is there a way to set the IPN to ONLY respond to store purchases? Or at least turn it off for PayPal invoicing?
PayPal system will auto generate this IPN warning email alert if your IPN listener endpoint URL fail to receive PayPal IPN response of the payments.
I request to please cross check and handle the "notify_url" parameter that your passing. Once merchant send a notify_url in API request call, PayPal system will send the payment IPN response to the specific url accordingly.
Please contact your website developer to check your IPN listener code, in order to stop this IPN warning email alerts.