Letterboxx

Letterboxx is a premium macOS application that transforms email newsletters into a clean, organized reading library. Instead of leaving newsletters buried in your inbox, it imports copies from Gmail, Outlook, or IMAP accounts into a searchable local collection where your favorite publications are easy to browse and revisit. The app includes custom Letterboxes, automatic sorting rules, favorites, reminders, highlights, quick filters, and full-text search to keep even large collections organized.

Clean View removes ads, tracking elements, and visual clutter for a focused reading experience, while built-in unsubscribe detection helps manage subscriptions. Designed with privacy in mind, Letterboxx stores your newsletter library locally on your Mac without ads or data selling. Its native macOS interface, keyboard shortcuts, themes, and seamless email integration make it an ideal home for newsletter readers.