I have a customer using SBS 2003 who in the past week has been receiving "License usage for a product licensed in per server mode has exceeded the maximum number of licenses purchased" messages. On a couple of occasions, users have been unable to log on or have been denied access to their Exchange mailboxes. After rebooting the server, users were able to log on properly again, but the problem repeated itself two days later. The SBS licensing showed a maximum usage of 18, with 15 installed licenses. I've told them that they need to order more CALs, and they have an order in the works. Is it the case that the SBS licensing service does actually deny connections when the license count is exceeded (it seems to be the case), and is there a way to view the users/devices that make up its count of maximum usage (they don't think there are more than 15 users connecting to the server)?