During the IIS log File Processor task in the OWA or Windows Mobile Default Gathering you will see the following error.
Unable to resolve the user domain\user with Device ID: DeviceIDXXXXXXXX into a known mailbox.
Report packs that are IIS Logs-based cannot report mailbox activity for linked mailboxes. The Windows Mobile report pack cannot not resolve user activity for mailboxes to which the user account is linked when the mailbox is a "linked mailbox". This affects all the reports under the Users folder.
Workaround: None
Status: Waiting for a fix in a future release of MessageStats.
