A mailbox that is located on an Exchange Server 2007 server may be identified as a legacy mailbox in Exchange Server 2007

A mailbox that is located on a server that is running Microsoft Exchange Server 2007 may be identified as a legacy mailbox in Exchange Server 2007. You may experience this issue in the following ways:

• The Recipient Type Status column in the Exchange Management Console displays LegacyMailbox instead of UserMailbox.
• Exchange 2007 mailbox tasks are not available for the affected mailbox.
  
  For example, the option to enable Exchange Server 2007 features is not present in the mailbox properties. For example, the Enable Unified Messaging option is not present.
• If you try to enable an Exchange 2007 mailbox feature by using the Exchange Management Shell, the operation fails. Additionally, you receive an error message at the command prompt.
  
  For example, if you try to enable the Unified Messaging feature in the Exchange Command Shell, you receive the following error message at the command prompt:
  Enable-UMMailbox : Property UMEnabledFlags cannot be set on this object because it requires the object to have version 0.1 (8.0.535.0) or later. Current version of the object is 0.0 (6.5.6500.0)

This issue may occur if the following conditions are true:

• The mailbox was created in the Active Directory Users and Computers snap-in on a server that was running Microsoft Exchange Server 2003.
• The mailbox was moved to an Exchange Server 2007 server.

To resolve this issue, correct the properties of the mailbox. To do this, use the Set-Mailbox command together with the ApplyMandatoryProperties parameter in the Exchange Management Shell.

For more information about the Set-Mailbox command, visit the following Microsoft TechNet Web site: