K-9 Mail APK

K-9 Mail

Overview

• K-9 Mail is a powerful, open-source email client designed for mobile users who prioritize privacy and flexibility.

• It is compatible with virtually every email provider, supporting standard protocols such as IMAP, POP3, and Exchange/WebDAV.

Core Features

1. Multi-Account Management:

• Seamlessly integrate and manage multiple email accounts within a single, streamlined interface.

2. Unified Inbox:

• View all your incoming messages from various accounts in one consolidated folder for improved efficiency.

3. Privacy-First Design:

• The application is built with strict privacy standards.

• It contains no tracking mechanisms and communicates exclusively with your designated email provider, ensuring your metadata remains private.

4. Efficient Synchronization:

• Stay updated with automatic background synchronization or instant push notifications for timely access to new messages.

5. Advanced Search:

• Perform both local and server-side searches to quickly locate archived correspondence.

6. OpenPGP Encryption:

• Support for PGP/MIME ensures secure communication.

• Users should install the "OpenKeychain: Easy PGP" app to enable full encryption and decryption capabilities.

Support

• If you encounter technical issues or have questions regarding configuration, please visit the official support forum at https://forum.k9mail.app to engage with the community and development team.

Contribute to Development

• K-9 Mail is now an official member of the Thunderbird family while maintaining its roots as a community-driven project.

• We invite contributors of all skill levels to help shape the future of the app.

• Whether you are a developer, designer, technical writer, translator, or bug triager, your expertise is welcome.

• To view our source code, report bugs, or explore the documentation, visit our repository at https://github.com/thunderbird/thunderbird-android.

• Joining our team is a great way to help ensure that a transparent, open-source email experience remains accessible to everyone.

FAQ

Q: Which types of email accounts can I connect to K-9 Mail?

A: You can use virtually any email provider with K-9 Mail because the application supports all standard industry protocols. This includes IMAP for constant synchronization, POP3 for local storage, and Exchange/WebDAV for compatibility with corporate or specialized email setups.

Q: Is it possible to manage my work and personal email in one place?

A: Absolutely. One of the core strengths of K-9 Mail is its robust multi-account management system, which allows you to integrate and switch between several different email accounts smoothly within a single, unified interface.

Q: How does the Unified Inbox feature improve my daily workflow?

A: The Unified Inbox feature consolidates all incoming messages from your various accounts into one single folder. This saves you from having to check each account individually, making your email management much more efficient and streamlined.

Version History

v20.0——6 Jul 2026

K-9 Mail is a 100% open source, privacy focused email client for Android Download the latest version of K-9 Mail to enjoy new features and updates immediately!

*20.0

New:

- Enable easily discoverable way to configure and use Thundermail

Changed:

- Only show message notification config actions above the cutoff

Fixed:

- Account drawer stayed open after account switch despite auto-select Inbox setting

- Imported settings could incorrectly show 'XX' avatar monogram

- Printed emails omitted message headers and used minimal margins

- Compose button did not work in tablet split-screen message view

*19.2

Fixed:

- K-9 Mail crashed when scanning Thundermail QR code

*19.0

New:

- Message notification actions can be configured

- Message font size scales with device preferences

- Integrate an easily discoverable way to configure and use Thundermail

Fixed:

- Thunderbird crashed on Android 8 when fetching images

- Accidental swipe in message viewer marked unread email as read