Creating a Resource

Any Exchange account can be a resource. Nothing special needs to be done in Exchange or Active Directory. There are three properties, stored on the account's personal free/busy message that control whether or not Outlook and Evolution treat it as a resource:

Connector doesn't currently provide any way to set these properties on a mailbox. (Outlook does.)

Of course, to be able to act as a resource, the account's Calendar must be writable by other users. (And the properties on the free/busy message must be readable as well. If you use the Delegates dialog in either Outlook or Evolution, it will make sure the free/busy message is readable to any user who can read the Calendar.)

Booking a Resource

Outlook's convention is that direct booking happens when all of the following are true:

If any of these criteria are not met, then it silently falls back to normal mail-based scheduling. (Among other things, this allows you to set up a resource such that some users can book it directly, but if anyone else tries to, it will just send a meeting request to that account, which can then be accepted or rejected manually by a secretary.)

If all the criteria are met, but the meeting must be rejected because of the settings of the PR_DECLINE_RECURRING_MEETING_REQUESTS or PR_DECLINE_CONFLICTING_MEETING_REQUESTS properties, then Outlook will pop up an error dialog explaining the problem, and refuse to save/send the meeting request.

If the resource can be booked, then Outlook will update the meeting request to show that the resource has accepted it, save that meeting request in the resource's calendar, and then send that meeting request to all of the remaining users (but NOT the resource) by mail.

Cancelation

If you cancel a meeting that has a booked resource, Outlook does not remove the event from the resource's calendar. Instead, it prepends "Cancelled: " to the event's summary and changes its TRANSP property to TRANSPARENT so that it no longer shows up as busy. This leaves the original event in the calendar, for record-keeping purposes, but allows a new event to use the resource instead.