class firewall::router::mail(
  $implementation = lookup('firewall::implementation', undef, undef, 'shorewall'),
  $destination, $zone = 'loc', $originaldest = $ipaddress
) {
  class { "firewall::implementations::${implementation}::router::mail":
    destination  => $destination,
    zone         => $zone,
    originaldest => $originaldest,
  }
}