Calendar Items Disappear From Microsoft Outlook 2003

Starting with Microsoft Exchange 2003 Service Pack 2 and Microsoft Outlook 2003 Service Pack 2 (you need both for this to be true) you may notice a strange - and maybe upsetting - behaviour of calendar appointments: they vanish randomly. The good news is that that the behavior is somewhat normal, but the bad news is that appintments do vanish.

Well, I've been working on truly understanding the situation, and - at this point - feel it is something users must be informed of, and learn how to work with. On the bottom of this article I'll describe the steps you should follow to duplicate this situation, as it may be critical to your business.

Basically, Outlook handles meeting requests differently now, and - for the most part - you will be faced with having to ACCEPT or DECLINE more appointments. Simply DELETING the notices from you inbox will also mean you will NOT have the appointment on your calendar, regardless of AUTO-ACCEPT features.

The work around to this entire issue is to Invite Attendees as Resources (New Appointment > To > Scheduling Tab > Add Others > Add From Address Book > add people to the Resources box). This will send the appointment without an opportunity to accept / decline.

To duplicate this issue:

1. Go to your personal calendar in Outlook 2003.
2. Create a new appointment, and invite someone else in the office.
3. Make sure that the other person has Auto Accept enabled. Also, for test purposes, choose a time that will not conflict with anything on the invitees calendar.
4. Send the appointment.
5. At this point the other user will see the appointment on their calendar, but will also have an ACCEPT notice in their inbox.
6. If you DELETE the inbox message, you will also delete this appointment.

Hope this information helps, you can read the details about the programming changes directly from Microsoft:

http://support.microsoft.com/default.aspx/kb/899919/en-us

Additionally, there was a bug in Exchange 2000 and Exchange 2003 (pre SP2) that had the same symptoms, and is corrected by hotfix 894470, but it does not apply to XCH SP2.