Want to send newsletters from directly inside your WordPress dashboard? You’re bored of switching to an external tool and want to do it in WordPress ?
Try Jackmail !
Jackmail Newsletters allows you to create a full email campaign suite into your WordPress dashboard.
Jackmail goes even further since they include a real professional routing platform.

The plugin itself, and all its feature is free. It also includes up to 3,000 emails per month for free.
You only have to pay if you want to send more than that. Prices are very cheap.