Prospect Mail
Unofficial email Outlook client using Electron. It uses the
Web App
and wraps it as a standalone application using Electron. This only works for
Microsoft/Office 365 accounts, don't use it for personal Outlook.com accounts.
Available for Linux, Windows (10+) and macOS.
> [!IMPORTANT]
> This project has NO DIRECT AFFILIATION with Microsoft, Microsoft 365 or any
> product made by Microsoft.
Download
The application can be downloaded from release page.
Select the appropriated file depending on your OS:
- Windows:
.exe file or .msi file
- macOS:
.dmg file
- Linux: Multiple artifacts are available, please choose your needed one
(
AppImage, deb, flatpak, pacman, rpm, snap, tar.gz) depending on
your Linux Distribution.
Installation
Windows
Just double-click and follow the Installer steps.
macOS
Double-click the dmg file and drag the blue Prospect Mail icon to the App
folder
Linux
Snap builds are available in the Snap Store.
Or use sudo snap install prospect-mail from the terminal.
Arch Linux has a community published artifact available in
AUR here.
For other distributions please follow your specific steps.
Screenshots
Features
- Check your Outlook Microsoft 365 emails/calendar from the desktop app
- Close to minimize
- Start minimized: toggle via tray icon Settings menu, or use command-line
flag
prospect-mail --minimized
- Dock tray support
- System notification
- Connect to standard or custom Outlook URL
- Spellcheck using native Outlook MS Editor
- Visualize files (pdf) in emails
- Automatic session recovery: expired auth cookies are cleaned at startup and
on wake-from-sleep; if the Outlook session expires, the app auto-reloads to
silently re-authenticate via SSO, and falls back to a desktop notification if
re-login is still needed
Settings
Via tray menu settings.json can be opened and edited. After every save you
need to click in "Reload settings" to apply changes.
Available Settings
{
"urlMainWindow": "https://outlook.cloud.microsoft/mail",
"urlsInternal": [
"outlook.cloud.microsoft/mail/deeplink",
"outlook.cloud.microsoft/calendar/deeplink",
"outlook.live.com/mail/deeplink",
"outlook.office365.com/mail/deeplink",
"outlook.office.com/mail/deeplink",
"outlook.office.com/calendar/deeplink",
"to-do.office.com/tasks"
],
"urlsExternal": [
"outlook.cloud.microsoft",
"outlook.live.com",
"outlook.office365.com",
"outlook.office.com"
],
"safelinksUrls": [
"outlook.cloud.microsoft/mail/safelink.html",
"outlook.office.com/mail/safelink.html",
"safelinks.protection.outlook.com"
],
"showWindowFrame": true,
"hideOnClose": true,
"hideOnMinimize": false,
"startupWindowState": "normal",
"showUnreadNotifications": true,
"unreadNotificationSource": "inbox",
"customBrowserPath": "microsoft-edge"
}
Setting Descriptions
| Setting | Description | Default |
|---|
urlMainWindow | Main Outlook service URL to load | https://outlook.cloud.microsoft/mail |
urlsInternal | Array of URL patterns for deeplinks that open in new app windows | See example above |
urlsExternal | Array of URL patterns for Outlook/Microsoft 365 services that open in the main window | See example above |
safelinksUrls | Array of URL patterns for Microsoft Safe Links that open in external browser | See example above |
showWindowFrame | Show/hide window frame and title bar | true |
hideOnClose | Minimize to tray instead of quitting when closing window | true |
hideOnMinimize | Hide to tray when minimizing (off by default: minimize stays in the taskbar; restore via tray → Show if enabled) | false |
startupWindowState | Window state on startup: "normal", "minimized", or "maximized" (also available via tray menu; --minimized flag forces minimized) | "normal" |
showUnreadNotifications | Show the "new messages" desktop notification (calendar reminders are unaffected; also available via tray menu) | true |
unreadNotificationSource | Which folders drive the unread badge and new-mail notifications: "inbox" (Inbox only) or "favorites" (sum of unread across your Outlook Favorites) | "inbox" |
customBrowserPath | Custom browser for external links. Use command name (e.g., "firefox") or full path | System default |
> [!NOTE]
> Settings from before 1.3.0 are migrated automatically on first launch:
> startMinimized/startMaximized become startupWindowState, and
> disableUnreadNotifications becomes showUnreadNotifications (inverted). No
> manual action is needed.
> [!NOTE]
> outlook.cloud.microsoft is Microsoft's unified-domain Outlook host and is
> now the default. The legacy office.com / office365.com / live.com hosts
> still work. Existing installs keep their saved urlMainWindow; use "Restore
> Default Settings" in the tray menu to adopt the new default.
Example Configuration for Personal Outlook
This configuration will let you use Prospect with personal Outlook.com account:
> [!WARNING]
> Please notice that Prospect Mail is only tested in Work/Educational accounts
> and no issues will be reviewed on use for personal accounts.
{
"urlMainWindow": "https://login.live.com/login.srf",
"urlsInternal": ["outlook.com", "live.com"],
"urlsExternal": ["outlook.com", "live.com"]
}
Architecture components
The main software architecture components and their versions are this:
Build
Clone the repository and run in development mode.
(You need to have git and node installed)
git clone https://github.com/julian-alarcon/prospect-mail.git
cd prospect-mail
npm install
npm start
Note: If you encounter a sandbox error on Linux, run:
ELECTRON_DISABLE_SANDBOX=1 npm start. See
CONTRIBUTING.md for details.
Build the application for Linux
npm run dist:linux
This will build AppImage, deb, pacman, rpm, flatpak, snap and tar.gz files in
the dist folder. These files can be run in most popular Linux distributions.
You can specify a specific build type:
npm run dist:linux:snap
npm run dist:linux:flatpak
npm run dist:linux:appimage
Build the application for macOS (arm64 and x64)
npm run dist:mac
Build it for windows:
npm run dist:windows
Install developer artifact
Once it has been built, or using the release files available, you can install
the files using:
- AppImage: Follow the AppImage
process
- Deb:
sudo dpkg -i prospect-mail_x.y.z_arch.deb
- Snap:
sudo snap install dist/prospect-mail_x.y.z_arch.snap --dangerous
- Flatpak:
flatpak install --user dist/prospect-mail_x.y.z_arch.flatpak
Contributing
Contributions are welcome! Please see CONTRIBUTING.md for
guidelines on how to contribute to this project, including development setup,
coding standards, and the release process.
License
MIT by
Julian Alarcon based on
electron-outlook by
Howard J