There are no monthly fees, only a $50 deposit to get started. You do not need to refer others, and you will earn a minimum of 4% a week on your deposit. You can withdraw weekly.
Make sure you check it out and you can register here:
This is the blog with information about Deliverer Safelist, the sorted safelist with reduced send switching to make it user friendly. You can use your regular mailbox. You can also download your own version and add your own addresses.