Usetiful - Fight user churn with great user onboarding. Interactive product tours and smart tips significantly improve your user retention.
Really Good Emails - A large collection of good product email design.
User Onboarding - Onboarding teardowns of popular sites/services
Good Sales Emails - Best sales emails from great companies
Userlane - Digital adoption platform with interactive guidance for software applications allowing anyone to understand and master any software from the get-go.
Great Email Copy - A dose of emails from around the web.