User A has Outlook 2007 in an Exchange 2003 SP2 environment. When User B sends a meeting request to User A, User A gets duplicate (2) meeting requests. User A is not a delegate of User B but does have full mailbox access.

Even when Administrator sends a meeting request to User A, a duplicate meeting request appears in the inbox. If User A sends a meeting request to User B, User B does not receive duplicates.

Again, no delegates here. No matter what I try, it still happens. Rebooted the Exchange server, restarted the domain controller, User A's machine, no difference. It even happens in OWA.

I can't seem to figure this one out. I have verified User A does not have a mobile device. Just straight up Outlook 2007 (and sometimes User A uses OWA when out of the office).

Anyone know of what could be causing this?

This fixed it!

http://support.microsoft.com/kb/253557

I had to log onto the user's workstation. I ran the MDBVu32 utility to remove a "schedule +" component. Somehow, along the way, the user was a delegate of themselves. I noticed it after following this article:

http://hellomate.typepad.com/exchange/2004...ng_which_e.html

I removed the "send on behalf" permissions in Active Directory but the issue still was experienced. The above KB article fixed it!

Thank you for posting the fix!!