Configuring the InterOrg Replication Tool

Reference: Inter-Organization Replication Tool Documentation contained in the InterOrg Download file.


The InterOrg Replication Tool is the answer for many organizations which want to synchronize public folder contents and free and busy data between their Exchange Organizations.

For other purposes like GAL synchronization and Identity Integration you can use IIFP (Identity Integration Feature Pack) which you can get free from Microsoft or MIIS (Microsoft Identity Integration Server). MIIS is not free but a powerful solution to synchronize different Directory Services.

The tool consists of two programs:

  • The Replication Configuration program (exscfg.exe) and the
  • Replication service (exssrv.exe)

The Replication Configuration program creates a configuration file for setting the following:

  • Replication frequency
  • Logging options
  • Accounts to use
  • Folders to be replicated

The Replication service, using a configuration file created by the Replication Configuration program, continuously updates information from the Publisher to the Subscriber. Schedule+ Free/Busy information is replicated from Publisher to Subscriber only.

You must have two free and busy sessions to bi-directionally update free and busy information. Public folders can be replicated from Publisher to Subscriber or bi-directionally. You can configure the replication frequency, the logging of messages and folder replication.

System Requirements

The InterOrg Replication Utility has the following requirements:

  • Windows 2000 Server with Service Pack 3 or later, or Windows Server 2003
  • Exchange 2000 Standard or Enterprise Edition with Service Pack 3 or later
  • Exchange 2003 Standard or Enterprise Edition


The installation of the InterOrg Replication Tool consists of the following steps:

Step One        Preparing the Publisher

Step Two        Preparing the Subscriber

Step Three      Installing the Inter-Organization Replication tool files

Step Four        Creating a Replication Configuration file

Step Five        Setting up the Replication service

Let’s begin

First we have to download the InterOrg Replication Tool from the following location:

Step One and Two – Preparing the Publisher and Subscriber

The next Step is to create two Windows Accounts with domain user rights and a mailbox in every Exchange Organization. It is important to understand that the service account and mailbox that you create must be listed as an owner of each public folder and subfolder you want to replicate, on either the Publisher or the Subscriber. This enables the tool to replicate anonymous and default permissions from one organization to the other. 

Create a public folder named ExchsyncSecurityFolder in the root Public Folder and grant Folder Visible permissions to the service account mailbox that you created for BOTH organizations. Do not specify any default or anonymous permissions on this folder; it is used by the Replication service for additional security and must be present on both the Publisher and Subscriber servers.

Step Three – Installing the Inter-Organization Replication tool files

We have to start exscfg.exe from the extracted ZIP file.

Figure 1: The Replication configuration program

Now we have to create a new Session Type “Public Folder(s) Replication.

Figure 2: Select the Session Type

Select a title for the Public Folder Session Configuration. You can specify the Maximum Tasks for this Configuration and a schedule how often this task will run.

For administrative purposes you can specify some Logging settings.

Under “Advanced” you can specify an alternative Account to connect to the Publisher- and Subscriber Organization.

Figure 3: Public Folder Session Configuration

Under “Folder List” you can select the Public Folders which you want to replicate. You can specify Subfolders, Deletions and Anonymous Access.

Figure 4: Modify the Public Folder List

Step Four – Creating a Replication Configuration file

After you have created the necessary configuration tasks you must save the configuration as a configuration file with an .ESC extension used by the Replication service.

Figure 5: Save the Configuration for the Replication Service

Step Five – Setting up the Replication service

Replication service (exssrv.exe)

Figure 6: Save the Configuration for the Replication Service

Click Install to configure the Replication service

Figure 7: Necessary Information for the Replication service

Specify Account Information for the service, the path to the configuration file and a working directory for the service.

Don’t forget to set the option “Automatic start at system boot”.

You can see the results in Outlook. It takes a while until you can see the replicated public folders.


The InterOrg Replication Tool uses RPC (Port 135) between the Publisher and Subscriber. An Exchange server monitors Port 135 for connections to the RPC endpoint mapper service.

When Exchange starts, it assigns two random ports < 1024 to use to communicate between the Exchange store and the Active Directory. Because these are random ports, it is difficult to establish communication because these ports cannot be opened on the firewall or proxy server. You have the chance to limit the communication with RPC to a fixed port. This is really Firewall friendly. For more Information read the Knowledge Base articles 155831 and 176466.


The InterOrg Replication Tool is a handy and easy to use Tool for Public Folder synchronization between different Exchange Organizations.

Related Links

Download Link for the InterOrg Replication Utility

Some Knowledge Base articles;en-us;229114;en-us;218960;en-us;221767;en-us;316022;en-us;265249;en-us;268801

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