Lists and Subscribers can be used for Mailing Lists via the Subscriber List integration for Sprout Reports. Mailing Lists can be used in Sprout Email and Sprout Forms.
If you have Sprout Reports installed when you install Sprout Lists, the Subscriber List Data Source will be installed for you and you will see a Subscriber List Report as an option in the New Report menu. If you installed Sprout Reports after Sprout Lists, visit the
Sprout Reports -> Data Sources tab to install the Subscriber List Data Source and make it available to Sprout Reports.