Email Kick - Email designer and analytics for your transactional emails.
Really Good Emails - A large collection of good product email design.
Email Love - Email design inspiration, templates and discovery
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.
Mail Marketing - Create mobile-friendly, easy-to-use newsletters in minutes. Fast. Effective. Simple. Send your e-mails to targeted receivers, get advanced reports. Profit.
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.