The OOFUrl element specifies the URL of the best instance of the Out of Office (OOF) Web Service for a mail-enabled user. It is an optional child element of the Protocol element (section 220.127.116.11.1.2.4). For more details about the services that are available at this URL, see [MS-OXWOOF].
The OOFUrl element is returned when the server implements a URL for internal or external access to the Out of Office (OOF) Web Service. If the OOFUrl element is omitted, the Out of Office (OOF) services are not available to the client.