Assuming you have a touch screen on your computer, open the Mail app by clicking it on the Start menu in Windows 10. The inbox listing is on the left and if you swipe left over an emai it reveals a green Archive tile underneath. Continue swiping and the email message will be archived (moved to the Archive folder).
Swipe an email header in the inbox listing to the right and a Set flag tile is revealed. Keep swiping and a flag is set against this message.
So there are two quick actions that can be performed by swiping on the screen with your finger. If you try these actions with the mouse it does not work. That is one benefit of having a touch screen.
You can actually configure what action each these left and right swipes perform. Even if you like the actions as they are, it is worth looking at the options that are available.
Click the gear icon in the bottom left corner of the Mail app and then select Options in the Settings panel that opens on the right side of the Mail window.
In the Quick Actions section at the top is a switch to turn swipe actions on and off. Below is swipe right and swipe left. Click the two actions lists and select the action you want to perform. For example, you might want to delete messages by swiping right over them. Use whichever actions you find most useful.
These are two simple time-saving tips for working with email in the Windows 10 Mail app, which, by the way, is much better than the Windows 8 version.