Mailspring's UI is open source (GPLv3) and written in TypeScript with Electron and React - it's built on a plugin architecture and was designed to be easy to extend. Check out CONTRIBUTING.md to get started!
Mailspring's sync engine is spawned by the Electron application and runs locally on your computer. It is open source (GPLv3) and written in C++ and C. For convenience, however, when you set up your development environment, Mailspring uses the latest version of the sync engine we've shipped for your platform so you don't need to pull sources or install its compile-time dependencies.
- Multiple accounts (IMAP & Office 365)
- Touch and gesture support
- Advanced shortcuts
- Lightning-fast search
- Undo send
- Unified Inbox
- Read receipts, link tracking, and more
- Mac, Windows, and Linux support
- Themes and layouts (including dark mode)
- Localized into 9 languages
- Advanced Search option
macOS (Intel and Apple Silicon) Windows and macOS