Mailspring

Mailspring is a native desktop email client for macOS, Windows, and Linux that supports multiple accounts via IMAP, Office 365, Gmail, iCloud, Outlook.com, Yahoo! and other providers. It offers a unified inbox, advanced Gmail‑style search across all accounts, and features such as read receipts, link tracking, scheduled sending, undo send, and quick‑reply templates. The composer includes spell‑check and grammar‑checking powered by LanguageTool, and the client can translate incoming and outgoing messages between several languages.

The application is open source and available for free, with optional paid Pro features. It provides customizable themes, dark mode, extensive localization into twelve languages, and deep integration with each operating system’s native UI elements. Users can create rich signatures with images and social links, and view calendar events and RSVP information directly within the client.

Mailspring targets users who manage multiple email accounts and need advanced productivity tools such as powerful search, translation, and grammar assistance, while preferring a desktop‑based, cross‑platform solution.