Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.
SendOut - Affordable email marketing for bloggers and influencers
MJML - The open source framework for responsive emails
rasa.io - Get more from your email list.
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.
Mailblast - Email marketing on a budget using Amazon SES