Paypal IPN not working on another paypal account

Question

We have this website that was running since September 2013 and relying on paypal IPN for user registration. However, this week we got a report from the client where 3 users was able to pay through paypal but was not registered into the site.

We temporary changed the paypal email('business' field) from the client's to another paypal account. Went through the process of registration and the IPN was successfully delivered. The user was created in the system, the IPN transaction was logged into our system. When we tried to changed it back to the client's paypal email account, but unfortunately the IPN did not reached through our system.

Here are some questions that I have in mind

• Does the type of paypal account (ie. business or personal account) matter when sending and receiving IPNs? Could this be a possibility? (even though last year it was working perfectly fine with the client's paypal account)

• We've been receiving this paypal email (below) for the past months. That email was appearing after a few months when we opened the site and we didn't even changed a single code from our IPN listener. Could this be the reason why the IPN was not sent when we use the client's paypal account? However, we always use the notify_url field since we have multiple IPN listeners.

  >Please check your server that handles PayPal Instant Payment
  >Notifications (IPN). IPNs sent to the following URL(s) are failing:
  >
  >http://<site>/payment/postback/
  >
  >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.
  

thanks,

Answer 1

Your IPN script is not completing successfully, so PayPal's server is not getting a 200 result back, which causes it to send repeat IPN's and will eventually disable itself as the message says.

Your web server logs should provide the info you need. Check there to see the history of the IPN script getting hit and you'll probably find some 500 results. Those should also provide the actual error that happened so you can get it resolved.

It's possible that some IPN's are working just fine but others are failing based on certain characters in payer information or other similar issues. You need to get all of that worked out in your IPN script so it can handle anything thrown at it.