The only WordPress plugin for emails you will ever need.
With Notification plugin you can notify anyone about anything. It has a bunch of triggers which will work out of a box. Want to get an email when someone will send a post for a review? Or maybe when someone update your custom post type? No problem!
You can just select a trigger, type in the email subject, content and set up unlimited recipients from a predefined list. To make it more alive you can use some merge tags which will be rendered while sending the email.
You can bundle this plugin with any other plugin or theme. Want some custom triggers? You can register them with few lines of code. There is also Settings API which you can use to add your own options.