Ink is a responsive email framework, used to make HTML emails look great on any client or device. It includes a 12-column grid, as well as some simple UI elements for rapid prototyping. The framework consists of the styles for a table-based grid, buttons, panels, retina images and more. Once the e-mail is ready, you can use the web-based Inliner tool to get all styles inline.
Ink, by Zurb comes under MIT-licensed and absolutely free to use.Ink