In Exchange 2013, 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.

Outlook Web App features can also be managed by configuring the Outlook Web App virtual directories. Virtual directory settings will be used for any mailbox that a mailbox policy hasn’t been applied to.

A default Outlook Web App mailbox policy is created automatically when Exchange 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 isn’t automatically applied to any mailboxes.

For information about creating or removing mailbox policies, see Create an Outlook Web App Mailbox Policy and Remove an Outlook Web App Mailbox Policy from Exchange.

The default Outlook Web App mailbox policy has all options enabled by default. For information about configuring Outlook Web App mailbox policies, see View or Configure Outlook Web App Mailbox Policy Properties.

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 by using the Exchange Administration Center (EAC) to modify an existing mailbox, or by using the Shell and the Set-CASMailbox cmdlet to apply a mailbox policy. For more information, see Apply or Remove an Outlook Web App Mailbox Policy on a Mailbox.