[Exim] Simple Exim AUTH

Hi,

I have never used AUTH before. I have a server running Exim 3.35.
There are ~5 people who use this machine to relay mail. I do not want
it to allow relaying to others, yet I cannot restrict based on IP, as
these people (and me) are on dial-ups.

I do not want the to AUTH against /etc/shadow, as these users are not
all in that file. What I was thinking of was a "shared secret" in
/etc/exim.conf, such that those who needed to send outgoing mail would
use a common Username/password pair. The client is most likely OE.

Help?

--
Sanjeev Gupta