The Coming Revolution in Email Design
Litmus Scope
Responsive email support » STYLECampaign »
CSS Support Guide for Email Clients | Campaign Monitor
CSS inliner
dwightjack/grunt-premailer
Responsive Email Patterns
Taking Our Email Campaigns to a Responsive Level by ZURB
Responsive Email | Email Design Reference
leemunroe/responsive-html-email-template
Responsive Email Design | Campaign Monitor
Responsive Email Resources
What Are Actions?