Microsoft has released the Calendar Checking Tool for Outlook and its available for download at the Microsoft Download Centre.
The Calendar Checking Tool for Outlook is a command-line program that checks Outlook Calendars for problems.
The tool opens an Outlook profile, opens the Outlook Calendar, and then checks several things such as permissions, free/busy publishing, and auto booking. Then, the tool checks each item in the calendar folder for problems that can cause items to seem to be missing or that might otherwise cause problems in the Calendar.
To use this tool, the Outlook calendar must reside on a Microsoft Exchange Server. The tool does not work with IMAP, with POP3, or with other non-Exchange mail servers.