Postmark is releasing a new feature called Layouts, which allows users to define common elements like CSS, headers, and footers, and reuse them across multiple Templates. This feature aims to simplify the process of managing templates by extracting common elements and making it easy to apply those changes across all templates. The feature was developed after extensive research and validation with customers, who preferred a more elegant solution over Partials, which is a commonly used approach in email providers. With this release, users can now create new Layouts independently or as part of creating a new Template, and the feature will be supported by various Postmark tools and libraries, including the API, CLI tool, and MailMason. The company encourages feedback from users to further improve the feature.