Paypal IPN Validation - Doesn't work despite success page being reached


Staff member
I've been bashing my head against a brick wall the last few days on minor problems. This time I am on the final piece to the puzzle. In my php function of a wordpress cart plugin I have the following:

Relevant Function - <a href="" rel="nofollow"></a>

Paypal Class - <a href="" rel="nofollow"></a>

I manage to go through the purchase fine. If I check on the sandbox account the seller receives the correct email from paypal and money etc. The case "IPN" in the function doesn't seem to work however. No email is sent with details. The success case is reached with a thank you page shown though. I don't understand how I could have missed anything. Any ideas?