I have Exchange 5.5 with Outlook 2000 Clients. I have been getting errors on the clients saying that I am out of CAL's. I have run the performance monitor on the Exchange for number of users and it shows that I am at the max number of users. However, when I go through and calculate who could be logged in, I am not coming up with the max. I have had to restart the exchange server a couple of times in the last few days because I installed Backup Exec on it and don't know if the restart is leaving connections open. Is there any way of seeing who the 45 CAL's that I have are being used by? I am using the concurrent-users-type licensing for the Exchange server.