It is my first time I was looking for a Newsletter plug-in. I read the description that you can manage as many contact as you want so it is already good. Infact I read among other plugins a limitation by a certain numbers. So when your website is growing and you get more and more users, unless you pay, you won't be able to manage extra users.
I downloaded the plug-in and activated. No issue at all. I created a Cron Job and was fine.
My advice is to test this plug-in with your own email before so you can experiment the themes and how the process involved to send the email works. Try a lot, send newsletter and check your email. All the fields into the setting section are fully explain. Also the author's website is rich of "how to do" materials. I recomment this plug-in.