Email Marketing Subscription Rules ( added in version 4.54.3 ) allow you to set up automatic actions when a user subscribes or unsubscribes to any of your mailing list.
This setting can be accessed from within the list under List -> Subscription Rules.
In the example below, we are setting up a rule to automatically remove subscribers from our “Prospects” list when they are added to the “Members” list.
Subscription Rules can also be used to establish groups of mailing lists that should be subscribed or unsubscribed from concurrently.
For more help maintaining your mailing lists, read this: Email List Management.