SaaS Email Templates - Responsive HTML email templates for SaaS startups
Pistachio Email Templates - Delicious newsletter templates built for automation
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.
Transactional Email Templates by Postmark - Open source email templates for use in your SaaS app.
Paperplane - High quality HTML to PDF conversion API for developers.
Sequencer by Close - The email drips top SaaS startups use to win more customers