With connectors in general, the best migration path is to build parallel connectors on Exchange Server 2003 systems. This way, the Exchange 5.5 connectors can remain intact and continue to route mail and perform directory synchronization with the foreign mail system.
The benefits of running connectors on both systems are as follows:
- Involves less risk when migrating the connectors
- Enables administrators to view Exchange 5.5 connector configuration when configuring and administering the Exchange Server 2003 connector
- Allows for controlled mail flow testing
- Provides a fallback plan if software defects or configuration issues are encountered with the Exchange Server 2003 connector
While testing the Exchange Server 2003 connectors, configure the Exchange Server 2003 connector with a higher cost and limited address space. This enables administrators to perform controlled tests of mail flow. When the organization is comfortable with the test results, the address space can be configured to match that of the Exchange 5.5 connectors. Also, the cost parameter on the connector can be dropped below that of the Exchange 5.5 connector, and the Exchange Server 2003 connector can begin routing all mail to the foreign system. The Exchange 5.5 connectors can remain in place until the organization is comfortable shutting them down.
Many Exchange 5.5 connectors also provide directory synchronization with foreign mail systems. Directory synchronization on the Exchange Server 2003 version of the connector should not be enabled until the mail flow through the connector works properly and the organization is ready to use the Exchange Server 2003 connector full-time. Most connectors such as GroupWise and Lotus Notes provide filtering options for directory synchronization. Marking the option Do Not Import Address Entries of This Type and using an asterisk (*) as a wildcard means that no entries will be imported and directory synchronization will remain on the Exchange 5.5 Server. Also do not export address entries to the foreign mail system, to avoid duplicate address entries in the foreign mail system's address list.
|Take screenshots of all connector configuration property pages before attempting to migrate any connector. A lost setting such as an address space entry that is not transferred to the Exchange Server 2003 connector can cause a major routing or directory synchronization disaster on both mail platforms.|
Migrating the Internet Mail Service
The Internet Mail Service has been replaced by several components in Exchange Server 2003:
- SMTP Connector
- Internet Message Format
- Message Delivery Properties
The Internet Mail Service needs to be replaced by an equivalent SMTP Connector in Exchange Server 2003. After the migration, the new connector must be reconfigured to match the settings of the old IMS.
Migrating Site Connectors
Site Connectors in Exchange v5.5 are replaced by Routing Group Connectors in Exchange Server 2003. Routing Group Connectors that communicate with Exchange 5.5 server communicate over RPC. When Routing Group Connectors communicate between Exchange Server 2003 systems, they communicate over SMTP.
To build parallel connectors to Exchange 5.5 sites, create a Routing Group Connector to the remote Exchange 5.5 site and configure the local bridgehead server as the new Exchange Server 2003 connector server.
Migrating foreign mail connectors
Exchange Server 2003 includes support for the following foreign mail connectors:
- GroupWise Connector
- Lotus Notes Connector
- X.400 Connector
The best strategy to migrating these connectors is to use a parallel connector strategy. The following configuration settings must be reconfigured after an upgrade is in place on the foreign mail connectors:
- Directory synchronization schedule
- Address spaces
- Import container and export container configurations
- Delivery restriction options, such as message size
Always prototype the configuration, mail transfer, and directory synchronization for foreign mail connectors in a lab environment before implementing them in production. Mistakes in foreign mail connector configuration are usually quite costly and require extensive clean-up on both sides of the connection.
Creating support for unsupported connectors
To support unsupported connectors such as the PROFS/SNADS, cc:Mail, and MSMail connectors, remain in Mixed Mode Exchange Server 2003 and leave an Exchange 5.5 site to handle the unsupported connector. For a long-term solution, consider an SMTP solution for mail transfer and LDAP for directory synchronization. Another solution is to locate a third-party replacement connector.
Migrating from Exchange Server 5.5 to 2003 -- 11 tips in 11 minutes
Tip 1: Comparing Microsoft Exchange Server 5.5 and 2003
Tip 2: Prerequisites for migrating to Exchange Server 2003
Tip 3: Structuring an Exchange migration for the best results
Tip 4: Preparing the Active Directory forest and domain
Tip 5: Installing and configuring the Active Directory Connector
Tip 6: Installing the first Exchange 2003 system in a 5.5 site
Tip 7: Understanding Exchange 2003 mailbox migration methods
Tip 8: Migrating Exchange Server 5.5 public folders to 2003
Tip 9: Migrating Exchange 5.5 connectors and services to 2003
Tip 10: Completing the migration to Exchange Server 2003
Tip 11: Best practices for migrating from Exchange 5.5 to 2003
This chapter excerpt from Microsoft Exchange Server 2003 Unleashed, by Rand Morimoto, is printed with permission from Pearson Education, Copyright 2005. Click here for the chapter download or purchase the book here.