Deleting a list
Before deleting a list you should ensure that you have exported all the data that you require, as list deletion will result in loss of user-specific campaign data (such as who opened an email) and data on who has unsubscribed. Be aware, list deletions are permanent and cannot be recovered.
If you're sure you want to delete your list, go to your "Lists" tab, click on the dropdown on the right-hand side of the list you wish to delete, and select "Delete". Then, confirm that you want to delete the selected list.