Domino Clustering and inotes

Do you know of anyone that has used the ICM and their success/ failures of using it? Speaking for myself, I never used it before, so I am treading on new ground here. We use a Postini spam/virus appliance that routes inbound and outbound mail through that appliance under the one domain name xyz.com. Then once the mail routes inside Postini to our network, It is currently configured to route and send mail through that one host name. Inside the DMZ, I was wanting to setup Domino Mail clustering for smtp traffic only and i notes redirection via ICM. Will the Cluster name hold the value of the domain of xyz.com for both servers? It appears that postini has a configuration for primary and failover server ip addresses, which, if I'm thinking correctly on this would handle the failover on the ip side if mail was impeded from postini to our smtp servers.  I'm just a bit confused on setting up the cluster to manage two servers with one host name of xyz.com. Any ideas or best practices? So in reference to the ICM and cluster, if equal # of mail files exist on server1 and same for server 2 which both servers run http, then I do not need  to use ICM?

Solution found. Thank you.