When installed, Winmail DAT Viewer 1.7 creates files in several locations. Instead of installing it by dragging its icon to the Application folder, uninstalling Winmail DAT Viewer 1.7 may need you to do more than a simple drag-and-drop to the Trash.
Winmail DAT Viewer 1.7 is a third party application that provides additional functionality to OS X system and enjoys a popularity among Mac users. Unlike the software developed for Windows system, most of the applications installed in Mac OS X generally can be removed with relative ease.
How to Uninstall Winmail DAT Viewer 1.7 Application/Software on Your Mac