Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.

Stensul - The Stensul Email and Landing Page Creation Platform lets marketers create emails and landing pages up to 90% faster.

MJML - The open source framework for responsive emails

Taxi for Email - Taxi for Email is a drag and drop email building for brand and agency teams. 

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.

Chamaileon.io - Design and create beautiful HTML emails and templates in any way you want with Chamaileon's collaborative email template builder platform. You can create nice emails in no time without coding. You can optimize email production to save time & effort.