smtp exim4 qpopper

[psye@brandeis.edu (John Thomas Langton)]

I've recently installed debian sarge, qpopper, and exim4 on my
machine.  Haven't changed the defaults at all and mail works locally
fine. However, if I try to connect with a client from a different
machine, mail does not work.

If I telnet to my linux box from my linux box it connects just fine,
but
if I telnet to it from the aforementioned client it can't connect.  

I've poured over docs, the config files, logs in /var, looked at
/etc/services and /etc/inetd.conf, have done a lot of trial and error,
and am stumped.

If someone could point me in the right direction I would greatly
greatly appreciate it.

thanks, 
John