[Exim] exim authentication + RBL

Hi, I'm new with exim but I'very impressed with it.

I'm having a problem to let my users do authentication to send e-mails
and use RBL at same time.

I'm using a exim 3.5 on a Debian system at Internet. My users are ADSL
subscribers. I configured exim to use RBL like that:

rbl_domains = relays.ordb.org/reject : \
              relays.visi.com : \
              sbl-xbl.spamhaus.org : \
              cbl.abuseat.org : \
              opm.blitzed.org : \
              dnsbl.sorbs.net

rbl_hosts = 0.0.0.0/0

When a user try contact exim to send an e-mail his connection is refused
and this message appears in the log file:

2004-08-10 20:33:21 recipients refused from
200165170253.user.veloxzone.com.br [200.165.170.253] (RBL
dnsbl.sorbs.net)

But my exim.conf has:

host_auth_accept_relay = *

Is RBL rules checked first than host_auth_accept_relay?

I know that put my user's IP address at rbl_hosts with a ! first will
make it works, but every time the IP address changes and put the IP
range will be very bad.

Anybody knows a way to make it works?

Thanks a lot!