mjml

MJML is a markup language created by Mailjet to reduce the complexity of coding responsive emails. It provides a semantic syntax and a rich library of standard components, which are compiled by an open-source engine into responsive HTML. The project supports multiple usage modes: a command line interface for compiling .mjml files to HTML, a Node.js API with extensive configuration options, a browser build (mjml-browser), and a free online editor. It also offers editor plugins for Visual Studio Code and Sublime Text. Key features include configurable output beautification and minification, CSS inlining with tag preservation, template variable sanitization, custom components via .mjmlconfig, and preprocessing hooks. The documentation details CLI arguments and Node.js options such as validation levels, include paths, and template syntax delimiters. MJML is suitable for developers and teams who want a maintainable, component-based workflow for email production.