These templates have been developed to work responsively across a variety of email clients including the often troublesome Outlook templates.
Zurb have released a similar number of responsive email templates however Antwort show greater support across more clients.
Antwort offers responsive layouts for email that both fits and adapt to client widths. Don't underwhelm desktop users with single column layouts that work for mobile. Antwort offers columns on desktop that automatically become rows on mobile.