Use the Instant Payment Notification (IPN) Simulator
The Instant Payment Notification Simulator sends mock notifications to a notification handler. The simulator is an excellent tool that can be used to verify your IPN handler is correctly processing the transaction notifications sent from PayPal.
To send a mock IPN message:
Navigate to Dashboard > IPN Simulator.
Populate the IPN Handler URL field with the URL of your IPN listener.
Select the type of notification you want to generate in the Transaction Type drop-down, and fill out the resulting form by specifying the details of the notification you need to test.
The IPN Simulator displays a default set of values for each notification type. By default, the simulator displays only the form's populated fields. Check Show All Fields at the bottom of the form to view all available fields for a particular notification type.
When the details are set, click Send IPN at the bottom of the form to send a single IPN message. The simulator displays the results of the operation at the top of the page.
Modify the simulator fields however you deem necessary. However, be aware that the simulator does not check the validity of your message field settings.
Test IPN handling in the Sandbox
The only difference between a notification sent from the Simulator and a live IPN message is that PayPal includes a
test_ipn variable in simulated notifications. To set up a sandbox account to handle IPNs, log in to the Sandbox test site (https://sandbox.paypal.com) using your sandbox account and proceed as if you're using a live account.
Note: See IPN Testing for more on testing IPN messages.