System requirements

Windows 10 build 1809 or later, or Windows 11
x64 (64-bit)
~250 MB free disk space

Install

Click Download above to grab the installer.
Run the .exe. SmartScreen will pop up — see below.
Follow the wizard. Default install path is %LOCALAPPDATA%\Programs\Mailwing.

First-launch SmartScreen

Mailwing isn't yet signed with an EV code-signing certificate (these cost a few hundred dollars a year — out of scope for an OSS project right now). Windows will show "Microsoft Defender SmartScreen prevented an unrecognised app from starting":

Click More info.
Click Run anyway.
Windows remembers your choice for subsequent launches.

Every installer artifact is built in the open by GitHub Actions — you can audit the full build provenance for the version you downloaded.

Install via winget

If you'd rather skip the SmartScreen dance and use Windows Package Manager:

powershell

winget install --id Mailwing.Mailwing

Make Mailwing your default mail client

Settings → Apps → Default apps → search "Mailwing" → set as the default handler for mailto links.

Troubleshooting

Antivirus flags the installer

Some antivirus products treat unsigned NSIS installers as suspicious by default. The binary is reproducible from the source on GitHub — feel free to verify or build yourself. Worst case, add an exclusion for the install path.

Mailwing won't start after install

Open Event Viewer → Windows Logs → Application and look for an entry sourced from Mailwing. Open an issue with the error text and we'll help.

How do I uninstall?

Settings → Apps → Installed apps → Mailwing → Uninstall. Account data lives at %APPDATA%\mailwing — delete that folder too if you want a clean wipe.