One nice feature of Exchange 2007 is the introduction of specific mailbox types, especially room resource mailboxes, which we create manually on AEMS at the request of departments outside of the EID system (since the associated Active Directory account is disabled for resource mailboxes).  Resource mailboxes can be configured to automatically accept meeting requests, and, if configured with the “AllowConflicts” parameter set to “$true”, can automatically accept conflicting appointments.  This can be handy for group out-of-office or vacation calendars.

Unfortunately, when a recurring item is submitted to such a calendar, specific instances which conflict with other items are declined, despite “AllowConflicts” being enabled.  According to Microsoft, this bug is by design. The only workaround is to create discrete one-time items, or to create a single event which spans multiple days.