Synopsis:
   set notify_userhost_automatic [on|off|toggle]

Description:
   If this is ON, several things occur. When on(5) notify_signon is
   hooked, a userhost(2) is issued on the person who signed on. The $2
   parameter of on(5) notify_signon is set to the person's user@host.
   When someone appears on the notify list whose hostname is already in
   the internal list, it won't query the server.

See Also:
   notify(1)