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.
Revue - The easiest way to create and send a curated newsletter
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.
MailChimp UX Newsletter - Tales of researching, designing, and building from Mailchimp
MJML - The open source framework for responsive emails
Letterfuel - Grow your audience with a curated newsletter