MJML - The open source framework for responsive emails
Pistachio Email Templates - Delicious newsletter templates built for automation
Email Design System for Sketch - Sketch file with 10 email templates for designers
SaaS Email Templates - Responsive HTML email templates for SaaS startups
Getform - Smart form endpoints. The modern way to build the form backend.
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.