In PPU Kiosk (Windows only) and PBU you can add a @domain address to the shortcuts above the keyboard when a guest shares through email. This is useful when for corporate events where many guests have the same email domain, e.g. @laphotoparty.com.
Type in your custom @domain in the text field at the top and click OK.
Click OK in the Preferences window and you're done! Now when a guest selects Email for their sharing option they will see the custom @domain as a shortcut above the keyboard on the right.
Congrats! You have created a custom @domain email button for your Windows Kiosk.