Mailook - Identify & fix your email deliverability issues for free 👀
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.
Sidemail - The simplest way to send transactional emails. Sidemail makes sending transactional emails trivial, it's perfect for side projects, MVPs or the next big thing.
MJML - The open source framework for responsive emails
Mailivery - Reach the Inbox, not the spam folder.
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.