# K-9 Mail review (2026): is it any good? > Open source email client for Android, now moving to Thunderbird Checked Nov 13, 2026 ยท graded Nov 13, 2026 by ToolGPA. K-9 Mail is an open source email app for Android built for handling large volumes of mail. It supports push IMAP, a unified inbox, multiple identities and GPG/PGP signing and encryption. The project's site now announces that Thunderbird for Android is available and describes it as the future of K-9 Mail. - **Category:** Email Apps - **Made by:** K-9 Mail - **Website:** https://k9mail.app - **Runs on:** Android - **Who should skip it:** Not for you if you use iPhone or a computer, as it is Android only. - **Facts last checked:** Nov 13, 2026 ## Pricing As of Nov 13, 2026, K-9 Mail is free to use. - **Pricing model:** Free - **Free plan:** Free to download from Google Play, F-Droid, GitHub Releases or Amazon; no paid plans are listed. - **Free trial:** None listed. | Plan | Price | What you get | | --- | --- | --- | | Free | $0 | Open source under the Apache License 2.0; the site has a donate link. | Read from https://k9mail.app/download on Nov 13, 2026. Prices change, so confirm with K-9 Mail before buying. ## Key features - **Push IMAP:** The feature list names push IMAP support, so new messages can arrive without polling on servers that allow it. - **GPG and PGP/MIME:** The site lists GPG and PGP/MIME support for signing and encrypting messages. - **Unified inbox and identities:** A unified inbox, per-account notifications and multiple identities are listed, along with signatures and BCC to self. - **Message handling tools:** Listed tools include message flagging, keyboard shortcuts, attachment saving and emoji support. - **Several ways to install:** The download page offers the Play Store (with a beta channel), F-Droid, GitHub Releases and Amazon. ## Good for - Android users who want an open source IMAP client - People who sign or encrypt mail with GPG on a phone ## Worth knowing - Android only; no iOS, desktop or web version is listed. - The site's banner says Thunderbird for Android is available now and calls it the future of K-9 Mail. - It is a client for existing mailboxes and does not provide an email address. ## ToolGPA grades **GPA: 2.8 out of 4**, graded Nov 13, 2026. K-9 Mail is a free, open-source email app for Android with push IMAP, a unified inbox, several identities and GPG signing. The project's own site now says Thunderbird for Android is the future of K-9 Mail. It is Android only and only a client, so it brings no mailbox of its own. - **Value for money: A.** Free to download under the Apache 2.0 licence, with no paid plans, and a donate link. - **Free plan and trial: A.** The full app is free from Google Play, F-Droid, GitHub or Amazon. - **Features: B.** Push IMAP, GPG and PGP/MIME, a unified inbox, identities and message tools. The listing shows no gap in the core job of a mail client, though it provides no address of its own. - **Ease of use: C.** No store rating on record. You add your accounts and server settings yourself. - **Platforms and integrations: D.** Android only: no iPhone, desktop or web version is listed. These are ToolGPA's own grades. Graded from this listing, whose facts were read from K-9 Mail's own pages on 13 November 2026. Not based on using the product, and shorter than our full reviews. ## Where it stands among email apps - K-9 Mail's GPA of 2.8 is higher than 88 of the 122 other email apps we grade, and level with 11. - It stands best on free plan and trial (A, above 97 of 122) and worst on platforms and integrations (D, above 0). - K-9 Mail has no paid plan. - On features, ease of use and platforms it scores 2.0 out of 4. Nothing scores higher for less, though at least one tool matches that score at a lower price. The category's chart of price against score: https://toolgpa.com/charts/email ## Keep it, or make your own? **Keep it.** K-9 Mail is free, so making your own would save you nothing. And it is not the kind of software a weekend replaces. It is one of the better ones too: its GPA of 2.8 is higher than 88 of the 122 other email apps we grade. - You could not: An email client: sending, receiving, threading and searching years of mail. - You could not: A real app for Android. Something home-made would be a web page. - You could not: The depth: we grade its features B, which means it covers the whole job. A judgement by ToolGPA from this listing, by rules that are the same for every tool. Nothing was built to test it. **Tags:** Email client, Open source ## Alternatives - [FairEmail](https://toolgpa.com/tools/fairemail): Open source, privacy-oriented email client for Android. [Compare](https://toolgpa.com/compare/fairemail-vs-k-9-mail) - [Thunderbird](https://toolgpa.com/tools/thunderbird): Free, open-source email app for Windows, macOS, Linux and Android. [Compare](https://toolgpa.com/compare/k-9-mail-vs-thunderbird) - [BlueMail](https://toolgpa.com/tools/bluemail): Cross-platform email client with a unified inbox and built-in AI. [Compare](https://toolgpa.com/compare/bluemail-vs-k-9-mail) - [Aqua Mail](https://toolgpa.com/tools/aqua-mail): Email app for Android and iOS that handles many accounts at once. [Compare](https://toolgpa.com/compare/aqua-mail-vs-k-9-mail) - [Edison Mail](https://toolgpa.com/tools/edison-mail): Free multi-account email app with one-tap unsubscribe. [Compare](https://toolgpa.com/compare/edison-mail-vs-k-9-mail) ## Sources The prices, plans, platforms and features above were read from these pages on Nov 13, 2026: - https://k9mail.app/ - https://k9mail.app/download - https://k9mail.app/about Page: https://toolgpa.com/tools/k-9-mail Listed by ToolGPA (toolgpa.com).