http://www.fromdoppler.com/resources.html
http://templates.mailchimp.com/resources/email-client-css-support/
https://github.com/mailchimp/email-blueprints
http://mailchimp.com/resources/guides/
https://github.com/charlesmudy/responsive-html-email-template http://www.charlesmudy.com/respmail/
http://blog.mailgun.com/transactional-html-email-templates/ https://github.com/mailgun/transactional-email-templates
http://webdesign.tutsplus.com/articles/creating-a-simple-responsive-html-email--webdesign-12978
http://www.emailonacid.com/blog/details/C13/html_boilerplate