The rebasing tool adds time zone information to appointments that it touches. This time zone information is the same that Outlook 2007 (and patched versions of CDO 1.21) puts on appointments when it creates them. These time zone structures are described here…
What that means is that we cannot discern between appointments that were touched by the rebasing tool and ones that were created or modified by “new” clients (Outlook 2007 or DST patched versions of CDO 1.21). There isn’t any marking on the mailbox itself so what you would have to do is iterate through items in the calendar folder and look for these properties on calendar items. If they exist on any appointment in the calendar then you know that the rebasing tool and/or “new” clients have been there.
You would need to use MAPI, CDO 1.21, or Outlook 2007’s object model to write this code. MAPI is not scriptable and you may not have Outlook 2007 available to you so I would suggest CDO 1.21. The following is a small VBA example which uses CDO 1.21 that you can run in Outlook which will pop up a message box telling you if new clients have been to this mailbox.
Dim oSession As New MAPI.Session
oSession.Logon , , False, False, , True
Dim oFolder As MAPI.Folder
Set oFolder = oSession.GetDefaultFolder(CdoDefaultFolderCalendar)
Dim oMessages As MAPI.Messages
Set oMessages = oFolder.Messages
Dim oAppt As MAPI.AppointmentItem
Dim oFields As MAPI.Fields
Dim oField As MAPI.Field
For Each oAppt In oMessages
On Error Resume Next
Set oFields = oAppt.Fields
Set oField = oFields.Item("0x825E", "0220060000000000C000000000000046")
If Not oField Is Nothing Then
MsgBox "New clients have been here."
…You can use this VBA code as the beginnings of a script to identify appointments that have been touched by the rebasing or “new clients”. If you don’t get any message box from this script that “New clients have been here” then you know either one of two things: 1) You don’t have any appointments in the calendar that you are the organizer of or 2) The rebasing tool or new clients have not touched any appointments in this calendar…
CDOLive: Property Tags and Types
BLOG: Outlook 2007 Time Zone Structures
GLEN: Creating a Summary Email of all appointments within a Users Calendar for given period
GLEN: Creating a Report of Meeting Organizers for all appointments in all calendars on a Server via WebDAV