[Exim] Update

Ok. Now that I feel totally stupid (Thanks Philip for pointing out the
obvious missing element in my config files!), can anyone help me with this
little issue?

I have a server with shadowed passwords. I want to maintain the password
security, but I also need exim to be able to read the passwords for
authentication purposes. I don't want to do the obvious (chmod o+r
/etc/shadow), but without doing that I cannot see hwo to SECURELY have exim
read the password database (unless it runs as suid root, which again, is not
safe).

Any help here is appreciated.

Thanks!