One needs a point of contact that is outside of the domain, as if anything happens to the domain emails, you would not be able to access them or get notifications.
To set or update your contact information:
Click on Contact Information:
Enter your primary email in the first text box and secondary (optional) in the next one.
Once set, you will get an email (notification) for each of the ticked actions:
Tick on events that you will want to be notified about and then click on Save (bottom of the page).