Open Source TypeScript Email Clients

Meron is a free, open-source email client designed to combine traditional email management with chat-style conversations and Kanban organization. It provides a unified inbox for managing multiple email accounts through IMAP and SMTP. Users can switch between conventional email, threaded chat, and Kanban board views. The software includes customizable tags, automated filtering rules, and rich-text message composition. It also supports RSS and Atom feeds for following online publications. Security features include encrypted local storage and credentials protected by the operating system's keyring. Optional Model Context Protocol integration allows AI clients to access permitted email functions. Available for Windows, macOS, Linux, Android, and iOS, Meron provides a flexible communication workspace.

Aster Mail is an open-source, privacy-focused email service with cross-platform desktop and web clients. It protects messages, subject lines, and attachments between Aster users through local end-to-end encryption. Its cryptographic system combines ML-KEM-768 and P-256 ECDH with X3DH and Double Ratchet protocols for post-quantum protection. Messages sent to external recipients can use OpenPGP encryption when their public keys are available. Users retain control of their encryption keys and can export them to compatible applications. Optional key publishing enables encrypted communication with external contacts. Its zero-access architecture prevents the service from reading protected message contents. Accounts can be created without providing a phone number or recovery email.

Proton Web Clients is a monorepo hosting the web applications for Proton’s suite of privacy-focused services, including the core Proton Mail webmail interface and related web apps like Proton Calendar, Proton Drive, Proton Account, Proton VPN, Proton Pass, and other connected tools. It consolidates all web client code, shared modules, dependencies, and development tooling into a single repository, enabling unified maintenance, consistency of design patterns, and efficient evolution of Proton’s online interfaces. These web clients run entirely in the browser, letting users securely interact with their email, calendars, files, and other services without needing native software installed, and benefiting from end-to-end encryption where applicable. The monorepo includes application logic, UI components, build scripts, and testing infrastructure for reliable deployments and streamlined continuous integration.

deltachat-desktop is an open-source, decentralized messaging application that enables private communication through email-based messaging infrastructure. It provides a familiar instant messaging interface while using interoperable standards instead of relying on a centralized messaging platform. Conversations are protected with end-to-end encryption designed to safeguard messages against unauthorized access. Users can exchange messages, share media and files, and participate in group conversations. The application supports multiple profiles and devices, allowing users to manage communications across different environments. Its chatmail relay integration simplifies account creation and communication with other users. Interactive web applications can run directly inside conversations, enabling collaborative activities, games, and shared tools. Built with Electron, the desktop client is available for Windows, macOS, and Linux and includes customization options.

Meru, formerly Gmail Desktop, is an open-source desktop email application designed to provide a dedicated Gmail experience outside the web browser. It allows users to access their Gmail inboxes through an independent application for Windows, macOS, and Linux. The software supports multiple Gmail accounts and provides native desktop notifications for incoming messages. It includes advertisement and tracker blocking to reduce distractions while managing email. Security features include confirmation prompts for unfamiliar links to help prevent accidental visits to suspicious websites. Meru also supports customizable Gmail styles and conversation display options. Built with Electron, the application processes email interactions locally while keeping messages within Google's infrastructure.