PayPal sandbox differs from Live mode

Question

So I've been struggling with PayPal's IPNs for a while now. I finally got everything working in sandbox mode, but when I went live, it didn't work.

Take a look at this:

Sandbox (Works and sends IPN)

<form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post">

Live (Doesn't send IPN)

<form action="https://www.paypal.com/cgi-bin/webscr" method="post">

See how the two payment screens are different? The sandbox one sends the IPN just fine, but the live one doesn't. Why could this be happening? Why is there a difference?

Answer 1

It looks like you have two issues going on here:

1. IPN was disabled on the merchant's account. This happens if PayPal receives continual failures when trying to send IPNs to you — PayPal will warn you by email first; if we're still unable to send IPNs to you after that, we'll disable IPN on the account entirely. I've re-enabled IPN on the account for you, but if this happens again in the future, you'll need to file a ticket with our Merchant Technical Support team to get it re-enabled.
2. I asked the system to re-send the IPN to you for the transaction you provided, but we're getting "404 Not Found" errors back from your website when we do. You might need to double-check that your notify_url is correct. In the future, you can ask PayPal to re-send IPNs from this page in your PayPal account.