Switch an Exchange Organization from Mixed to Native Mode
After upgrading an existing organization to Exchange 2000 or creating a new Exchange organization, if you are certain you will not need to install an Exchange 5.5 server or connector, you can switch your organization to native mode.
To switch an Exchange organization from mixed to native mode:
Important If your Exchange organization is in native mode, you cannot change it back to mixed mode or install earlier versions of Exchange.
Related TopicsUnderstanding Exchange's Modes of Operation Understanding When to Switch an Exchange Organization to Native Mode