Closing Mailspring's window doesn't quit the app. It keeps running in the background — syncing mail, showing notifications, sending scheduled messages, and returning snoozed threads — and lives in your menu bar or system tray. Click the tray icon to bring the window back.

Starting with your computer

In Preferences > General, check Launch on system start. Mailspring will start hidden in the tray at login.

• Windows: this option only appears for the standard installer. If you installed with Scoop or another package manager, or the option isn't working, press Win+R, run shell:startup, and put a shortcut to %LocalAppData%\Mailspring\Mailspring.exe in the folder that opens. Add --background to the end of the shortcut's Target so it starts minimised.
• Linux: the option writes ~/.config/autostart/Mailspring.desktop and only works in XDG-compliant desktops. On other setups, run mailspring --background from your session startup script.
• macOS: Mailspring registers itself as a login item, which you can also see under System Settings > General > Login Items.

The tray icon

Show icon in menu bar / system tray (Preferences > General) turns the icon on or off. On Linux, restart Mailspring for the icon to disappear, and install libappindicator or libayatana-appindicator if no icon shows at all. How the icon indicates new mail is set in Preferences > Appearance.

Quitting completely

To stop Mailspring entirely — before uninstalling, moving its data folder, or when a folder it created keeps reappearing on your server — choose Quit from the tray icon or from the application menu (Cmd+Q on macOS, Ctrl+Q elsewhere). Make sure the icon is gone from the tray.