Odd Appointment issue
 

I have a user that when ever she is included as an attendee the sender gets a
bounce back (5.1.1) from a previously deleted account.

Exchange 2003 sp2, Outlook 2k3

User X & Y are still with the company and have active accounts. User Z was
deleted from the system. User X invites user Y to meeting and User X gets a
bounce saying user Z no longer exsists. Only happens on users Ys account,
User X can be any account on the system.