Exchange 2003 Auto Accept Agent vs. direct booking
Published Feb 22 2006 03:29 PM 25.8K Views

In my Exchange support experience, customers often ask me about the differences between using the Auto Accept Agent and Outlook Direct Booking. They want to know which they should use for their specific environment. After much research, I compiled the following matrix of advantages and disadvantages of each to help you decide for yourself which you should use.


The Auto Accept Agent is a server-side store event sink available in Exchange 2003 SP1 which provides automatic server-side processing of meeting requests sent to resource mailboxes. The Agent handles initial scheduling, cancellations and updates and sends responses to the meeting organizer - meaning less scheduling conflicts and allowing receptionists and conference room owners to spend their time more productively.


What are the advantages of using Auto Accept Agent?


  1. The agent runs on the server 24 hours per day, 7 days a week. The agent responds immediately and the requestor does not have to wait for the receptionist to return from lunch.

  2. The agent checks the availability by looking at the calendar (resource schedule), not the Free/Busy information. This reduces the number of issues caused by free/busy update lag.

  3. It can decline individual conflicting instances within a recurring meeting request.

  4. In case of declined meeting request with conflicts (or a meeting request accepted with conflicts) the response includes date/time information on which instances conflict.

  5. All comments and attachments are removed from the meeting requests. Only the time and date information will remain on the meeting item. This prevents the delegate from viewing and confidential or private information. It also keeps the mailbox trim.

  6. Meetings marked as private are processed immediately. Additionally, the private flag is stripped from meeting requests so the receptionist will always have clear visibility to what is on the calendar.

  7. It replaces the need for excessive permissions needed to allow direct booking and does not require delegate permissions or configuration

  8. Much more robust than Outlook "auto-booking".

  9. Reminders are removed from the conference room's copy of the meeting.  This avoids "reminder hell" in the event the conference room mailbox is directly opened in Outlook.

  10. It handles meeting requests from all clients including OWA.

  11. The resource mailbox owner retains their rights on the resource mailbox and will remain the ultimate authority on the mailbox.

Does Auto Accept Agent have any disadvantages compared to direct booking?

  1. The agent code must run on every Exchange server that has a resource mailbox, since CDOEX is used to process requests and can only access local mailboxes.

  2. Delegates (e.g. Receptionists) will be less aware of the number and nature (urgency) of incoming requests.

  3. Currently the booking window will be limited to 6 months. This can be changed but it's not recommended. It will take a while for requestors to become accustomed to this hard limit. Important: Any request beyond the six-month window, including recurring meetings extending past it, will automatically be declined.

  4. Delegates will have to check the Inbox, Sent Items, and Deleted Items for unexpected items, but can do so more infrequently.

With that said, I would also like to talk about direct booking and its advantages and some considerations while using it.


Why direct booking?


Direct booking is an Outlook-specific feature that uses the organizer's Outlook client (Outlook 2000 or later) to book an appointment directly into a resource mailbox schedule. The Outlook client of the person organizing the meeting performs all the necessary tasks, such as conflict checking and placing the reservation on the resource calendar. To set up direct booking, follow:


291616 How to direct book a resource in Outlook 2002 or in Outlook 2003;EN-US;291616


Advantages of Direct booking:


  1. Immediate confirmation/denial of booking request.

  2. It has the logic to avoid double-booking.

With these advantages in mind, some disadvantages of Direct booking include:

  1. Direct booking requires granting organizer read/write permissions on the calendar. Hence, users can just go onto the resource's calendar and delete existing meetings to free up space for their own meetings.

  2. Organizer must remember to designate resource as "Resource" and not "Required" or "Optional". No conflict checking is done if resource specified as one of the latter (rule on resource's inbox should be created to generate reply to this effect).

  3. Since there is availability against free/busy, latency in free/busy replication can result in double-booking.

  4. Conflicts aren't detected beyond the range of published free/busy and can result in double-booking.

  5. Outlook Web Access does not currently support the "direct booking" of meeting requests.

Direct booking should not be used in conjunction with automatic booking done by the Auto Accept Agent. There is also configuration associated with direct booking that could conflict with Auto Accept Agent settings. For example, the default setting for direct booking is to accept all requests, regardless of conflicts. There is also a direct booking setting that automatically declines all recurring requests. These settings are only honored by Outlook and only when the resource is specified as a resource attendee. You should not register a resource mailbox for Auto Accept Agent in Exchange 2003 when you set up a resource for direct booking in Outlook. This is discussed in the below article

903290 You should not register a resource mailbox for Auto Accept Agent in Exchange 2003 when you set up a resource for direct booking in Outlook;EN-US;903290


Cluster Server Installation Notes


I also get asked if the agent can be installed on a cluster. Installing the Auto Accept Agent on a cluster requires only minor considerations. The installation of the binaries is the same as installing on a standalone server. However, Auto Accept Agent must be installed on each node that may be used for failover. If Auto Accept Agent is not installed on a passive node, meeting requests will be orphaned in the resource mailbox Inbox if this node is made active. Since the agent starts only when needed, there is no need to change the service startup settings. Because the configuration is file-based, it is important to use the same settings across all nodes in the cluster. If Auto Accept Agent is running on multiple active nodes, any per-mailbox settings must be put in all AUTOACCEPT.CONFIG.XML files. This file can be copied to all nodes of a cluster.


Mailbox sink registration must be done using the active node which hosts the mailbox. Although passive nodes must have Auto Accept Agent installed, they are not actually running Exchange services and are incapable of performing the mailbox registration. There is no need to make a node active to install or remove the Auto Accept Agent.


In next blog post: Troubleshooting Auto Accept Agent top support issues.


- Nagesh Mahadev

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