Polymail - Native email app for email productivity.
Journal - Organize all your ideas
Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues
Day One - A simple journal application for the Mac, iPhone, and iPad. AboutTo learn more about Day One, see these two excellent reviews . PublishPublish is not available in Day One 2.
Airmail - Airmail is a lightweight and lightning fast mail client for Mac.
Journalistic - A simple, yet powerful micro journaling app