Outlook 2003 non-invited attendee's receiving meeting invites

I have user A, B, and C. A is the intended Receiver of the invites. User A
which is receiving invites through Outlook 2003. When you send user A an
invite user B and user C receive the same invite which was not intended for
them. I've checked all permissions and delegates and they have no connection
what so ever. User B has access to user A's inbox and has never been a
delegate on user A's machine. I removed user B's permissions to access user
A's Inbox. And still the same problem. User C has never had any connection
with any of the users. Could this be a connection between a deleted account
or a group of some sort in exchange or AD. I'm not sure what else to do I
have been working on this for way to long and need a resolution for this once
and for all. Any help would be appriciated.