Whitelisted IP Addresses
This is an advanced configuration parameter. If you misconfigure whitelisted IP addresses, your application will be broken.
By default, the application can perform API calls from any IP address. By configuring whitelisted IP addresses for your application, you can control the source IP addresses for the API calls made by your application. In this case WePay will reject any API calls made with your application credentials from any other IP address with an error code 1014.
You can specify the whitelisted IP addresses using semi-colon separated list of either individual IP addresses or IP addresses ranges.
Follow the link for more information on how to obtain your Rackspace outbound IP addresses: Rackspace outbound IP Addresses.
18.104.22.168; 22.214.171.124; 126.96.36.199 - 188.8.131.52
To configure this setting, go to the Advanced section of the "Configure" tab of your app dashboard.