HTMLEmail.io - Responsive HTML email templates for startups & developers
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.
Pistachio Email Templates - Delicious newsletter templates built for automation
MJML - The open source framework for responsive emails
Transactional Email Templates by Postmark - Open source email templates for use in your SaaS app.
Stripo - Stripo is an all-in-one email design platform. We enable our clients to build emails of any complexity, including interactive AMP emails, really fast and easy.