We're building a simple tool to help us with our group emails, we wanted something simple, you define (or import) your contacts information, organize them in lists, compose messages, pick lists where a message go to, and let the system work the magic.
You can use mail-merge variables in messages, and the tool allow you to preview all emails before you send them. The cost of using the tool will be 1 cent per email, only for the sending part, the organizing of contacts/lists/messages is all free.
The tool is built with a responsive UI design to work well on small screens.