Manage Inter-Organizational Replication
You can share public folder and free and busy information between two or more organizations using InterOrg Replication Utility. Before running the utility, create a mailbox-enabled account and assign permissions on the server that is publishing the information and the server that is receiving the information. Then use the two programs, the Microsoft Exchange Server Replication Configuration utility (Exscfg.exe), and the Microsoft Exchange Server Replication Service (Exssrv.exe) to coordinate meetings, appointments, and contact information between members of two different Exchange organizations.
To set up InterOrg Replication Utility, complete the following steps in order.