Limiting Calendar Conflicts

Admin wants to limit conference room scheduling. The Auto Accept agent in Exchange 2003 does the trick.

• By Bill Boswell
• 09/07/2004

Question: I have a quick Exchange question for you. We're setting up meeting rooms as resources and we want to limit how far in advance meetings can be scheduled. We don't want people setting meetings further than three months in advance and, in particular, we don't want recurring meetings being set with end dates six months or more in advance because our rooms tend to get booked and then not used. Is there a way to do this? We are running Exchange 2000 but will be upgrading to Exchange 2003 by the end of September.
— David

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Answer: As it turned out, David found the answer before I could reply. I want to share what he found.

In June of this year, Microsoft released a tool specifically designed to handle requests sent to resource mailboxes. A "resource mailbox" is a mailbox that represents a conference room, department laptop, piece of audio/visual gear, or any other item that can be reserved for individual use.

The tool is called the Auto Accept agent. It's available as a free download that you can get by clicking here. The documentation for the agent is available at this link. The agent only works with Exchange Server 2003.

The Auto Accept agent installs via an MSI package. You must install it on each Exchange server that hosts resource mailboxes. The installation package does not extend the Active Directory schema nor does it store configuration information in Active Directory.

The agent itself consists of an "event sink," a piece of code that waits for an event to occur then takes an action. The agent listens for incoming meeting requests sent to registered mailboxes. When the agent is notified of an incoming meeting request, it looks up the time and date in the Calendar folder of the resource mailbox to determine if there are any scheduling conflicts.

If the requested time is clear, the agent accepts the meeting request and returns a reply to that effect. If the resource has already been booked for the requested time period, the agent declines the meeting request and returns a message informing the scheduler of the conflict. The agent does not suggest alternate times. The agent can also decline a recurring meeting due to a conflict. You can assign a booking window to the agent so that it only accepts reservations within a certain interval during the day, or within a certain end date.

It's important to note that the Auto Accept agent looks in the actual Calendar folder of the resource mailbox, not in the free/busy system folder where calendar information is published. This avoids potential scheduling conflicts that might occur if the resource mailbox schedule has not yet been updated in the free/busy folder.

Once installed, the agent is configured using a Visual Basic script called RegisterMailbox. This script flags a resource mailbox to tell the Auto Accept agent to monitor incoming meeting requests. Once you've used RegisterMailbox to identify a resource mailbox, the rest of the magic happens automatically. You can use RegisterMailbox to assign a delegate to the resource mailbox — that is to say, a human user who can open the Calendar folder in the resource mailbox and make changes manually to the scheduled events.

This is a great tool, well documented and simple to operated. It's well worth your time to evaluate it for use in your organization.

Until next time.