Email Standards Project : The Email Standards Project is about working with email client developers and the design community to improve web standards support and accessibility ...
HTML email templates : Easily create beautiful, branded email marketing campaigns. Start by choosing one of our free HTML email templates and customize it in minutes.
Email-Blueprints : Email Blueprints is a collection of HTML email templates that can serve as a solid foundation and starting point for the design of emails.
Pattern Tap : Organized Web Design Collection of User Interfaces for Inspiration and Ideas. The CSS Gallery Alternative
Ink : A Responsive Email Framework from ZURB. Quickly create responsive HTML emails that work on any device & client. Even Outlook.