2.2.4.1.1.2.5 AlternativeMailbox
The AlternativeMailbox element contains information that enables clients to open an additional mailbox. It is an optional child element of the Account element (section 2.2.4.1.1.2). <6>
The AlternativeMailbox element is returned only when an alternative mailbox is associated with the user.
The elements specified in the following sections can be child elements of the AlternativeMailbox element.