Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Topic Last Modified: 2011-04-28

When you're upgrading your existing Microsoft Exchange Server 2003 organization to Exchange Server 2010, there's a period of time when both Exchange 2003 and Exchange 2010 will coexist within your organization. This section discusses key points about both the upgrade process and coexistence as they apply to the Client Access, Transport, and Mailbox server roles.

You can only deploy Exchange 2010 in an Exchange 2003 organization that operates in native mode. Use Exchange System Manager to change the Exchange organization to native mode on an Exchange 2003 server, as follows:

  1. Start Exchange System Manager. Click Start > Programs > Microsoft Exchange > System Manager.

  2. Right-click the organization, and then click Properties.

  3. Click the General tab, and then, under Change Operations Mode, click Change Mode. Click Yes if you are sure that you want to permanently switch the organization's mode to native mode.

For more information, see the following topics:

Checklist: Upgrading from Exchange 2003

Upgrade from Exchange 2003 Client Access

Upgrade from Exchange 2003 Transport

Upgrade from Exchange 2003 Mailbox

For more information about the Exchange 2003 to Exchange 2010 planning and upgrade process, see the following topics:

Exchange 2003 - Planning Roadmap for Upgrade and Coexistence

Understanding Upgrade to Exchange 2010

Managing Deployment of Exchange 2010

Exchange Server Deployment Assistant