http://zurb.com/playground/responsive-email-templates
-> they use floats for columns and don't support Outlook 2007, 2010, 2013
http://www.campaignmonitor.com/guides/mobile/
-> good old campaignmonitor
http://internations.github.io/antwort/
-> they use align:left for columns and display block for smaller resolutions
http://www.emailonacid.com/blog/details/C13/emailology_a_free_responsive_email_template_using_media_queries_-_part_i
-> also align:left and simple devicewidth class (no display block); good testing email app
