Outlook 2010 Meeting Invitation forwarding issue

Question

I am having an issue with what I am assuming is a delegation access issue for a user in my office.

User A used to work under Manager B and all meeting invitations would go to both User A and Manager B. User A has since moved to a new department and is working under Manager C. While meeting invitations should only now be going to User A and Manager C, they are still also coming to Manager B.

I confirmed this by sending a blank meeting invitation to User A from my computer and checking Manager B mailbox. She did receive the invitation that I sent.

I check the delegation settings for User A and made sure that it is not set up to forward to Manager B. There are currently no users set up to be delegates for User A.

One interesting thing to note is on Manager B's Outlook, the invitation to the meeting sent to User A has an error stating "Cannot open Calendar folder for User A. The operation failed", and above that the message "This meeting is not in the Calendar, it may have been moved or deleted."

I have attached a screenshot of the meeting invitation as it appears on Manager B's outlook.