Malachi Mail
Download

Download

The current version is 0.1.2, released on 26 October 2026. Linux and macOS have ready-made downloads; the Windows app is built from source until it can be handed out.

Ready

Linux

x86_64 and aarch64. Flatpak, or a native package for a distribution with libadwaita 1.7 or newer.

Every version's files stay on the releases page.

Ready

macOS

macOS 14 or newer, Apple silicon and Intel. The app is built with Swift and AppKit and brings the engine with it.

Signed with a Developer ID and notarised by Apple: it opens without a warning. Open the image and drag Malachi Mail to Applications. SHA-256 77e2701d9c772fbf396159b541f61e343328cf438052bd5fdaab8c6469b9dbe9

Download for macOS

From source

Windows

Windows 11, x64 and ARM64. The app is built with C# and WinUI 3 and brings the engine with it.

The app folder the build makes is unsigned and has no installer yet; handing it to others waits for a licence decision on the Microsoft components it carries. Until then, build it from source.

Build on Windows

Flatpak

There is no Flathub listing yet. Download the bundle for your architecture and install it; it pulls the GNOME 48 runtime from Flathub.

flatpak install --user ./malachi-0.1.2-x86_64.flatpak

Ubuntu does not ship Flatpak any more, so it takes one step first:

sudo apt install flatpak
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

The Flatpak is the build that updates itself: install a newer bundle over it and the data stays. The ChatGPT provider of the assistant is not available in the Flatpak build.

.deb and .rpm

The native packages link the system GTK 4, libadwaita and WebKitGTK instead of carrying a runtime, so they need libadwaita 1.7 or newer: Ubuntu 26.04 LTS, Debian 14 and Fedora 42, but not Ubuntu 24.04 LTS, whose libadwaita is 1.5. On 24.04 take the Flatpak.

sudo apt install ./malachi_0.1.2-1_amd64.deb      # Debian, Ubuntu
sudo dnf install ./malachi-0.1.2-1.fc42.x86_64.rpm   # Fedora

There is no apt or dnf repository, so a package installed this way is not updated by apt upgrade or dnf upgrade. Unlike the Flatpak, these put malachi-mcp on PATH, which is what an MCP client needs to start it.

Where your data goes

Mail, settings and the local store live in the platform's application-data directory: ~/.local/share/malachi on Linux (inside the Flatpak's sandbox for the Flatpak), ~/Library/Application Support/Malachi Mail on macOS, %LOCALAPPDATA%\Malachi Mail on Windows. Passwords are in the system keyring. Nothing is sent anywhere but your own servers.

From source

The repository builds on all three platforms: Go 1.25 and GTK 4.18 for the Linux client, Xcode's Swift 6 toolchain on macOS 14, the .NET 10 SDK on Windows 11. The steps for each platform are in the build instructions.

Early version. 0.1.2 reads, writes and sends mail on real accounts every day, but it is still an early version. Keep a second mail program for anything that matters, and read what's new before updating.