Set up the Replication Service
To set up the inter-organizational replication service, use a utility to install the configuration file and specify the domain account name. You can then start the service from the same utility. You can also use Service Control Manager to start the replication service.
To install and start the replication service:
Note For each mailbox on the source server that you want to replicate free and busy information to, a corresponding custom recipient must exist on the destination server. The unique key that matches mailbox to custom recipient is the SMTP address of the mailbox, so these SMTP addresses must be identical.