Answer
While logged on as administrator it is possible to force any user off the system. Ending a user session in this way is often known as killing the user.
To kick a user off the mail server while they are logged on, go to the Administration > Mail > Security > Who section and select the user you wish for force to log off. Once selected, click on the "logoff" button and the user will have their session terminated.
This feature is useful if a user has left their terminal but not logged off the server.
Keywords:kill kick terminate force off