Upgrading to Exchange 2007

Microsoft Exchange Server 2007 will reach end of support on April 11, 2017. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.

Applies to: Exchange Server 2007, Exchange Server 2007 SP1, Exchange Server 2007 SP2, Exchange Server 2007 SP3

Transition is the scenario in which you upgrade an existing Exchange organization to Microsoft Exchange Server 2007. To perform the transition, you must move data from the existing Exchange servers to new Exchange 2007 servers. For example, when upgrading from an Exchange Server 2003 or Exchange 2000 Server organization to an Exchange 2007 organization, you perform a transition.

Migration is the scenario in which you upgrade to Exchange 2007 by migrating data from a non-Exchange messaging system to Exchange 2007 or from an existing Exchange organization to a completely new Exchange organization, without retaining any of the Exchange configuration data in the first organization. For example, when merging with another company, you can perform a migration. In this scenario, you move mailboxes and data to the other company's Exchange organization, without retaining any of the configuration data from your existing Exchange organization. Another example is when upgrading from Lotus Notes to Exchange 2007, you perform a migration. In this scenario, you must move mailboxes and data to the new Exchange 2007 organization, without retaining any of the data from the Lotus Notes organization.

The transition process happens in several phases. In each phase, you introduce individual Exchange 2007 server roles and transport features. At the conclusion of each phase, the organization will have coexistence of Exchange 2007 with Exchange 2003 or Exchange 2000 and will be running in a supported coexistence mode. The end-to-end process is designed to maintain messaging functionality and stability throughout the transition process. For more information about establishing coexistence and managing servers when Exchange 2007 coexists in the same organization with Exchange 2003 or Exchange 2000, see Coexisting with Exchange Server 2003 and Exchange 2000 Server.

The migration process includes installing a completely new Exchange 2007 organization, and then migrating mailboxes from the old messaging system to the new Exchange 2007 messaging system, using various tools for migration.

You can migrate from Lotus Notes to Exchange 2007 by installing Exchange 2007 in a new organization and migrating existing mailboxes. You can only transition to Exchange 2007 from the following existing messaging systems:

• Exchange 2003 messaging system

• Exchange 2000 messaging system

• Combined Exchange 2003 and Exchange 2000 messaging system

This means that if you are upgrading from an Exchange 2003 or Exchange 2000 organization, you can choose to either transition the organization, or migrate to a new organization. In most cases, you will want to retain the Exchange data from the existing organization, and so you should choose to transition to Exchange 2007.

If you are upgrading from any messaging system besides Exchange 2003 or Exchange 2000, your only option is to migrate to Exchange 2007.

Figure 1   Transition and migration phases

Supported Scenarios

The following table lists the supported transition and migration scenarios.

Table 1   Supported transition and migration scenarios

For More Information

The following provides more information about how to transition to Exchange 2007.

• Single forest to single forest
  If you have an existing single forest Exchange 2003 or Exchange 2000 topology, you can transition to a single forest Exchange 2007 organization. For more information about how to deploy Exchange 2007 in this scenario, see How to Transition from Single Forest to Single Forest.

• Cross-forest to cross-forest
  If you have an existing cross-forest Exchange 2003 or Exchange 2000 topology with Exchange servers and mailboxes in each forest, you can transition to an Exchange 2007 cross-forest topology. For more information about how to deploy Exchange 2007 in this scenario, see How to Transition from Cross-Forest to Cross-Forest.

• Single forest to cross-forest
  If you have an existing single forest Exchange 2003 or Exchange 2000 topology, you can transition to a cross-forest Exchange 2007 topology. For more information about how to deploy Exchange 2007 in this scenario, see How to Transition from Single Forest to Cross-Forest.

• Resource forest to resource forest
  If you have an existing Exchange 2003 or Exchange 2000 topology, and you already have a resource forest that has either Exchange 2003 or Exchange 2000 in the dedicated Exchange forest, you can add an Exchange 2007 server to that dedicated Exchange forest and move existing mailboxes to the new Exchange 2007 server. For more information about how to deploy Exchange 2007 in this scenario, see the topic How to Transition from Resource Forest to Resource Forest.

• Single forest to resource forest
  If you have an existing Exchange 2003 or Exchange 2000 topology, and you do not have a resource forest topology, but you want to deploy Exchange 2007 in a dedicated Exchange forest, you will first have to deploy Exchange 2007 in a combined cross-forest and resource forest scenario. You will have some Exchange mailboxes in the existing Exchange 2003 or Exchange 2000 forest and some Exchange mailboxes in the Exchange 2007 resource forest. If you want to move all your Exchange mailboxes to the Exchange 2007 forest, you will have a single resource forest scenario. For more information about how to deploy Exchange 2007 in this scenario, see the topic How to Transition from Single Forest to Resource Forest.

For More Information

For more information about migrating from Exchange Server 5.5 to Exchange 2007, see Migrating from Exchange Server 5.5.

For more information about migrating from Lotus Notes, see Migrating from Lotus Notes.

For more information about Microsoft partners who provide Exchange 2007 migration solutions, see Exchange Server 2007 Partners: Migration Solutions.