[exim] How to mail hub properly?

Hi, I'm looking to setup my exim4 as a mail gateway to another mail system on the same server.

I have exim4 running on port 25 to receive mail. The other commercial mail system runs on port 26.
199.60.230.1 is the mail server with MX mail.mydomain.com
The config file looks like this:

# This is a Debian specific file

dc_eximconfig_configtype='internet'
dc_other_hostnames=''
dc_local_interfaces='199.60.230.1'
dc_readhost=''
dc_relay_domains='mydomain.com'
dc_minimaldns='false'
dc_relay_nets='199.60.230.0/24'
dc_smarthost=''
CFILEMODE='644'
dc_use_split_config='true'
dc_hide_mailname=''
dc_mailname_in_oh='true'
dc_localdelivery='mail_spool'

I have a file called /etc/exim4/hubbed_hosts

mydomain.com:            127.0.0.1::26

The router file looks like this:

# router/150_exim4-config_hubbed_hosts
#################################

# route specific domains manually.
#
# see exim4-config_files(5) and spec.txt chapter 20.3 through 20.7 for
# more detailed documentation.

hubbed_hosts:
  debug_print = "R: hubbed_hosts for $domain"
  driver = manualroute
  self = send
  domains = "${if exists{CONFDIR/hubbed_hosts}\
                   {partial-lsearch;CONFDIR/hubbed_hosts}\
              fail}"
  same_domain_copy_routing = yes
  route_data = ${lookup{$domain}partial-lsearch{CONFDIR/hubbed_hosts}}
  transport = remote_smtp

Do I have my config correct for a high volume mail server?
The idea is to have exim4 receive mail, do some RBL checks, virus scan etc. and
then pass the mail onto the real mail server thats running on the same box.
Just not sure if this is the most efficient way for exim in this scenerio.

Thanks!
Cheers,
Mike