I am getting this error email from paypal on regular basis and orders are not showing up as well because paypal doesn't signal my website that payment is done. Nothing was changed to website recently but suddenly this happened. Here is email. Please check your server that handles PayPal Instant Payment Notifications (IPN). IPNs sent to the following URL(s) are failing: paypal_retun.php 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. Thank you for your prompt attention to this issue. Thanks, PayPal
Hello, paypal_retun.php should probably be paypal_return.php ? Also, is that the full URL paypal is giving you? No actual website URL?