Hello,

Our server configurations are,

PHP 5.5.36
Mysql 5.6.30
Zencart v1.5.1

We are getting a continous Paypal mail regarding the 'PayPal Instant Payment Notification Warning'.

===================
Dear George,

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

https://www.gointernational.co.uk/ipn_main_handler.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.

Yours sincerely,
PayPal

Could you please help me to solve this issue.

Regards,
Pramitha

We are using Paypal Express checkout. We are not using PayPal Website Payments Standard. So do we need to enable IPN on PayPal? Can we turned off this IPN notification from paypal.

At the moment, not sure if the issue is more because of using ZC 1.5.1 or some other reason. ZC 1.5.5.a has been issued and PayPal has made changes to their side since the time ZC 1.5.1 was issued some four years ago.

IPN handling using PayPal Express let's the store get updated when it receives and is able to process the "message".

One question is what has changed since the last time that a successful purchase was processed? Has there been changes to the htaccess in the store's root if one was added? (ZC does not require an htaccess file in the store's root for a base install.)

The fact that you are being notified about the ipn handling not working indicates that in the PayPal account, IPN handling has already been turned on. Might want to verify the settings.

Take a look at "Similar Threads" on the bottom of this page, especially the first thread with a good explanation by DrByte.

One thing is for sure: when I click on your posted link, I get "Nothing to process. Please return to home page." and that indicates that there is nothing wrong with your file.