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 BOILERPLATE : This website and its sample code creates a template of sorts, absent of design or layout, that will help you avoid some of the major rendering problem...
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.
Ink : A Responsive Email Framework from ZURB. Quickly create responsive HTML emails that work on any device & client. Even Outlook.