In simple English
Penguin Mail is a desktop program for reading email and checking your calendar. It connects to Gmail, Microsoft Outlook, and standard mail accounts, keeping your messages right on your computer. You can organize your inbox, set up automatic replies, and encrypt your messages with security keys. It costs nothing to use, and your data goes straight from your device to your mail provider without stopping on a middle server.
What it is
An email client and calendar application built with GTK4 and libadwaita, written in Rust. It supports IMAP, POP3, Gmail, and Microsoft services, alongside OpenPGP and S/MIME encryption.
What it is good for
Solo builders who want a fast, native email app on Linux or macOS that respects their privacy, avoids web browsers, and works with multiple providers in one place.
- Keeps your email cache and credentials locally on your computer.
- Includes an optional AI assistant that works with local models or API keys.
- Supports GnuPG encryption and verification for secure messages.
- Requires specific modern system libraries for GTK and WebKit on Linux.
- Flatpak and Snap packages isolate the app, blocking local assistant scripts and terminal tools like Claude Code.
- macOS builds are currently unsigned and require a manual bypass on first launch.
webmail interfaces or heavy Electron-based email clients
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sudo curl -fsSLo /usr/share/keyrings/penguin-mail-archive-keyring.gpg https://c9dev.github.io/penguin-mail/penguin-mail-archive-keyring.gpg sudo curl -fsSLo /etc/apt/sources.list.d/penguin-mail.sources https://c9dev.github.io/penguin-mail/penguin-mail.sources sudo apt update && sudo apt install penguin-mail