Really Good Emails - A large collection of good product email design.
SaaS Email Marketing Handbook - Double Your MRR With Email Marketing
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.
HubSpot Free Email Marketing - Powerful drag and drop email marketing in the HubSpot CRM
Email Design System for Sketch - Sketch file with 10 email templates for designers
Elevatr Email Marketing Automation - Fast and easy email marketing software