[exim] Relaying denied. Proper authentication required

Can anyone help me, I am trying to setup exim on Fedora core 4 with a smarthost. I installed the basic version from
# yum install exim*
and then I added the following smarthost router:

remote_smtp_smarthost:
        debug_print = "T: remote_smtp_smarthost for $local_part@$domain"
        driver = manualroute
        domains = *
        transport = remote_smtp
        route_data = "smtp.server.isp.com"

However I get the following error message:

LOG: MAIN
** root@??? R=remote_smtp_smarthost T=remote_smtp: SMTP error from remote mail server after RCPT TO:<root@???>: host mail.westnet.com [216.187.52.7]: 550 5.7.1 root@???... Relaying denied. Proper authentication required.
LOG: MAIN
Frozen (delivery error message)

I added passwd.client to the /etc/exim/ directory and added the following authenticators:

plain_login:
        driver = plaintext
        public_name = PLAIN
        server_prompts = Username:: : Password::
        server_advertise_condition = ${if eq{$tls_cipher}{}{no}{yes}}
        server_condition = ${lookup{$1}lsearch{/etc/exim/passwd.client}{${if eq {$value }{$2}{yes}{no}}}}{no}}
        server_set_id = $1

cram_md5_login:
        driver = cram_md5
        public_name = CRAM-MD5
        server_advertise_condition = ${if eq{$tls_cipher}{}{no}{yes}}
        server_secret = ${lookup{$1}lsearch{/etc/exim/passwd.client}{$value}fail}
        server_set_id = $1

But I setill get this error.
Can anyone tell me what I need to do in order to get exim to authenticate with my smarthost

Many thanks de Chris G