MailBrush` is a Node.js package that allows developers to add syntax highlighting to code snippets in HTML emails, making them easier to read and understand. It supports a variety of programming languages, including HTML, CSS, JavaScript, JSON, PHP, HTTP, and Bash, and can be customized with different colors and styles. The package works with all major email clients, including desktop and mobile versions, as well as web-based mail services like AOL, Gmail, Outlook.com, and Yahoo. Installation is straightforward, requiring only the installation of Node.js, and can be automated through email workflows to reduce manual overhead. Once installed, users can run a simple script to generate HTML markup for their code snippets, which can then be used in email templates.