Questions about Using

Questions about Using 010

When I enable the Drag & Drop option and download the installer and install it, even I already open Denbun, another Denbun window is open.

This is the behavior due to the specification of the D&D control when you install it for first time.
When you install it for first time, message composing screen is switched to the Email main screen, two main screens remain. You should close one of them.