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
HTMLEmail.io - Responsive HTML email templates for startups & developers
Email Testing By Inbox Pirates - Preview, Analyze & Test emails with one click.
Startup Emails - Responsive HTML email templates for startups
iMailair - We all know that email is broken.
Good Email Copy - Email copy from great companies.