Overview
MJML (Mailjet Markup Language) is a high-level, component-based framework designed to solve the historical complexity of responsive email development. By 2026, MJML remains the industry standard for developers seeking to bypass the arcane 'table-hell' of legacy email client rendering. Its architecture uses a semantic syntax that the MJML engine transpiles into optimized, Outlook-compliant HTML. This process ensures consistent behavior across over 50+ email clients, including various versions of Microsoft Outlook, Gmail, and Apple Mail. The framework operates on a 'Responsive-by-Design' philosophy, where the engine automatically handles complex media queries and fluid layouts. Technically, MJML is built on React for the engine and offers a robust CLI, an online editor, and a standard library of UI components. Its market position is solidified by its extensibility, allowing teams to create custom enterprise-grade components that enforce brand consistency while reducing development time by up to 70% compared to raw HTML/CSS coding.