PayPal IPN failing

Received this in an email:

Please check your server that handles PayPal Instant Payment Notifications (IPN). Instant Payment Notifications sent to the following URL(s) are failing:

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.

We’ve received this email daily for the past week so it is very concerning.

Hello @rigid_ink,

There is nothing to worry about concerning that email, but nevertheless I do encourage you to contact [email protected] and let them verify your setup to make sure all is in order (just in case).

Best regards,