[exim] Variable for remote MX server

Hi,

Right now, when my mail plateform is having issues to deliver messages to a
particular remote server (blacklist, routing problem, ...), I usually route
these messages via a smart host located in another netwok, based on the domain
name of the recipient :

smart_relay:
  driver = manualroute
  condition = "${if or{\
                        {eq{$domain}{domain1}} \
                        {eq{$domain}{domain2}} \
...
                      }"
  transport = remote_smtp
  route_list = * MY_SMART_HOST

I'd like the condition to be based on the remote server name or IP. Is there any
way to retrieve this information in a router ?

Thanks.

Christian