> Can that be right? Is the shell really aware of the
> remote terminal or is the firewall/sendmail box 
> spawning an xterm on itself?

The shell really is aware of the remote terminal.  Some environment settings
are passed on when you connect to a remote machine (e.g. see the scrub_env()
function in /usr/src/libexec/telnetd/sys_term.c).  The environment variable
TERM is one that is passed on.  This means that you can use full screen (i.e.
curses-based) programs on remote machines without either your display being
garbled or having to specify a terminal type.

J

-- 
                    My other computer also runs NetBSD
                          http://www.netbsd.org/