You will be presented with multiple options for handling email via Postfix. Details about each option will be displayed, so feel free to select the option that best fits your needs and click OK.
Next, you will be prompted to enter a system mail name. Feel free to put any mail name of your choice and a system mail address will be created for you.
The setup process will continue. If there are any issues, be sure you have the proper permissions in place in GitHub. If you do not have the proper permissions to copy certain repositories, this can halt the entire process.