Select the list you wish to create an email alert
Go to Settings and select General.
You will see the follow options for Email Alerts:
Summary: Gives you a daily email of all new subscribers and unsubscribes.
One-by-One: You can receive email alerts every time a customer subscribes or unsubscribes from your list.
To receive alerts just add the email address that the alerts will be sent to.
When finished, click the Save Changes button at the bottom of the page.