You need to have Splunk Enterprise installed and configured. To do so, please refer to the official documentation.
Configuring the extension
1. Log in to Splunk.
3. You can start configuring immediately once the application is installed.
3.1 You can also configure the application on the Apps page. Click on Set up next to the application name.
4. Fill in your API key and click on Save.
Using the extension
1. On the Reverse MX lookup page you can perform instant Reverse MX lookups.
2. To integrate Reverse MX lookup into your script you can use the command wxareversemx. It takes 2 arguments: mail_server, where you provide the search term, api_key (optional), where you can provide your API key, otherwise it will be taken from a config file.