K-9 Mail

K-9 Mail is a powerful, open-source email app designed to make handling your inbox easy, fast, and secure — whether you manage one account or many. Now part of the Thunderbird for Android family, it offers advanced features tailored for both everyday and expert users.

K-9 Mail App Features

K-9 Mail is designed with privacy, efficiency, and control in mind.

Push IMAP Support

• Get real-time email updates using push notifications.
• Saves battery by only connecting when new mail arrives.

GPG & PGP/MIME Support

• Built-in support for encrypted email using OpenPGP.
• For full functionality, pair it with OpenKeychain: Easy PGP.

Per Account Notifications

• Customize alert tones and vibration per account.
• Manage work and personal inboxes with separate settings.

Unified Inbox

• View emails from all your accounts in one place.
• Easily switch between accounts or manage them together.

White and Dark Theme

• Choose the look that fits your mood or environment.
• Dark mode saves battery and is easier on the eyes at night.

Signatures

• Add personalized signatures for each email account.
• Supports text or custom formatting.

BCC to Self

• Automatically BCC yourself for better record-keeping.

Message Flagging

• Mark important messages for easy reference.

Multiple Identities

• Send from different names or email aliases with one app.

Keyboard Shortcuts

• Power users get productivity boosts with quick-access keys.

Attachment Saving

• Save email attachments locally with a tap.

Emoji Support

• Express yourself in style — emojis included. 😎

…and Many More Features Inside!

• Multiple account support
• Local & server-side search
• Background sync
• No tracking or ads
• Open-source, community-driven

Need Help?

Ask questions or find answers at our Support Forum.

Join the Community

K-9 Mail is part of the Thunderbird open-source family. Developers, translators, testers, and all contributors are welcome.

Contribute on GitHub: https://github.com/thunderbird/thunderbird-android

Download K-9 Mail

• Google Play
• F-Droid
• Amazon Appstore