If you do not recognize this URL, you may be using a service provider that is using IPN on your behalf. Please contact your service provider with the above information. If this problem continues, IPNs may be disabled for your account.
If Instant Payment Notifications are turned on in your PayPal Account or your 3rd Party Shopping Cart is requesting them then PayPal will send a message about transactions to the URL that is listed in your PayPal Account (or the value of the URL your 3rd Party Shopping Cart sent to PayPal).
If you are using a shopping cart typically the Instant Payment Notifications are used to communicate to your shopping cart that the payment was complete. This allows your shopping cart to update your orders to show that they were paid.
If you receive an IPN failing warning email, it typically means that the portion of your shopping cart (Instant Payment Notification listener) is no longer responding to the PayPal Server. When this happens we send a warning email to you so that you can contact your shopping cart provider or your web developer to ensure that the Instant Payment Notification responses are being received.