I have an Exchange 2010 infrastructure with Outlook 2010 clients. Several of my users are complaining about Outlook not delivering meeting requests to the inbox, but automatically accepting the meeting request and placing it in the user's calendar. All checkboxes at File -> Options -> Calendar -> Auto Accept/Decline... are unchecked. As far as I can tell, the users have not turned on any options or rules to automatically accept meeting requests. Has anyone ever heard of this phenomenon in an Exchange environment? This is very odd, and appears to be at random.