My company has about 100 customers that have a server that we need to make sure there backup is successful and antivirus is properly working. Without much of a budget for this project, I decided to look at Exchange 2003 that is supplied in our action pack subscription for this project. I thought I would create each customer an account in my little email domain and have them email to another email account in the same email domain, that mail box would be monitored. Each customers would have no reason to access their coresponding mail box since these would applications sending the email for a failed backup or a detected virus. Would I need a CAL for each customer? If so is there another option?