In Exchange 2010, you can create multiple Outlook Web App mailbox policies and apply them to individual mailboxes. When an Outlook Web App mailbox policy is applied to a mailbox, it will override the settings of the virtual directory.

In previous versions of Exchange, Outlook Web App features were managed by configuring the Outlook Web App virtual directories. Exceptions for individual mailboxes were accommodated by enabling or disabling features on individual mailboxes.

A default Outlook Web App mailbox policy is created automatically when the Client Access server role is installed. By default, all options are enabled on the default Outlook Web App mailbox policy. You can create as many Outlook Web App mailbox policies as necessary to meet the needs of your organization.

Note:
The default Outlook Web App mailbox policy is not automatically applied to any mailboxes.

For example, you may want to create a policy that forces users to use WebReady Document Viewing to view attachments or a policy that limits users to the Light version of Outlook Web App.

You can use the Exchange Management Console or the Exchange Management Shell to create and configure Outlook Web App mailbox policies.

Only one Outlook Web App mailbox policy can be applied to a mailbox.

If there's no Outlook Web App mailbox policy applied to a mailbox, the settings defined on the virtual directory will be applied.

An Outlook Web App mailbox policy can be applied to a mailbox as part of the new mailbox wizard, by using the EMC to modify an existing mailbox, or by using the Shell and the Set-CASMailbox cmdlet to apply a mailbox policy.