The Test Postback Tool allows you to simulate a postback to make sure that it is functioning correctly. This is done by firing postbacks that will result in either a success or error message. The first step is to navigate to the page by selecting Affiliates>>Postbacks.

The next step is to select the control menu of the postback you would like to test, and click Test.

Now, you are at the page to test the postback. Start by pasting the desired URL, and selecting an offer to go with it. Then select Continue (when you click Continue a window of the pasted URL will load). 

You will then get to a page where you can see which postbacks are being fired. If these are correct, click Continue again. 

Once the postbacks are fired you will receive a confirmation. It will show you data for Conversions on top and Postbacks underneath. You can see if there was an error from the Success or Error message at the bottom, or by checking the Status which is the first column for Conversions and the seventh column for Postbacks. When you are finished, click Done.