SketchCasts - A weekly screencast, all about how to use Sketch
Really Good Emails - A large collection of good product email design.
GoRails - Ruby on Rails screencasts for Web Developers
Email Love - Email design inspiration, templates and discovery
Sketch Talk - A community for Sketch users of all skill levels
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.