Direct Mail is an email marketing solution for Mac that allows users to create and send personalized emails to subscribers. It includes customizable email templates, image editing, live previews, custom email sign-up forms, automatic and manual list segmentation, email tracking, campaign analytics, subscriber activity reporting, and more. Users can customize emails with images, videos, buttons, surveys, and more, and use conditional logic to tailor content for each recipient. The app also includes "Spam Tests" to alert users to mistakes before sending.