Pkg exim4 users - Jan 2008 - exim4 smarthost configuration help

Hi all.

First of all, let me start saying that I''m a total nb as far as mail
server
administration is concerned (it''s not my primary job).

I have a machine (pallino.cace.local) on the internal network running debian 
4.0, behind
a NAT.

I want to configure exim4
- not to manage any local mailbox for the users on pallino.cace.local
- to forward all the messages directed to the local users to an external
SMTP server (mail.cacetech.com) external to the network
- to rewrite the local recipients and local sender with the addresses in
/etc/email-addresses (e.g. root: gianluca.varenni at cacetech.com)

I configured exim4 as smarthost, forwarding the emails to mail.cacetech.com.
That works perfectly, including TLS authentication, i.e. if I run "echo foo
| mail -s test foo at gmail.com" the mail gets sent correctly.

The problem. The sender address gets rewritten properly (root -->
gianluca.varenni at cacetech.com), the local recipient don''t get
rewritten
properly.

So if I run "echo foo | mail -s test gianlucav" the mail gets sent to
gianlucav at cacetech.com (instead of gianluca.varenni at cacetech.com)

The update-exim4.conf.conf file is the following one

# /etc/exim4/update-exim4.conf.conf
#
# This is a Debian specific file

dc_eximconfig_configtype=''satellite''
dc_other_hostnames=''cace.local''
dc_local_interfaces=''127.0.0.1''
dc_readhost=''cacetech.com''
dc_relay_domains=''''
dc_minimaldns=''false''
dc_relay_nets=''''
dc_smarthost=''mail.cacetech.com''
CFILEMODE=''644''
dc_use_split_config=''false''
dc_hide_mailname=''true''
dc_mailname_in_oh=''true''
dc_localdelivery=''mail_spool''

email-addresses is the following one

# This is /etc/email-addresses. It is part of the exim package
#
root: gianluca.varenni at cacetech.com
gianlucav: gianluca.varenni at cacetech.com

Can you point me in the right direction? I looked around for some easy guide
on it, but I couldn''t find anything useful (maybe I''m just
blind)?

Thanks in advance
GV