Outlook Meeting Update Problem

Some things to look at:

1.) Are they, perhaps, moving the meeting to a Personal Folder instead of leaving it in the Exchange folder?

2.) Another thing to look for would be message rules that may be playing with the original meeting request.

3.) Then, you might also look to see if they have shared their calendar with someone or given access privaledges to someone who might be deleting it on their end.

4.) Look at the properties of this person's calendar folder as compared to someone elses calendar to see if there is something different, like autoarchive, that has been set differently.

This would be one of those "Technician Intuition" things. You would probably have be there to watch what this person does, from beginning of creating a meeting in the first place, right up through and including what they do when an update to the meeting is sent. Can you have them create a test meeting while you sit and watch what they do? You'll need one required attendee and one optional attendee on the list. Watch to make sure they're inviting attendees from the correct address book/contact list (there is a local list and an online list). Then, wait and see what happens when they reply.

Let us know what you find.