The maximum number of registered user profiles is limited inside the server computer, based on the maximum disk space the server computer confines to such purpose. For example, consider an environment where users can get registered themselves using a web interface. In this case the web interface must know how much disk space is available before proceeding to register new mail accounts inside the server computer and this way preventing any disk writing when there isn't enough free space on disk to perform a new user registration. Considering the server computer has confined 1GB of disk space to handle the mail service (e.g., mail queues, mailboxes, etc.) and each user mailbox is 10MB, it will be possible to provide self-registration through the web interface for 100 users in total. Another measure related to save disk space might be to remove unused user accounts and their related files (e.g., mailboxes) from the server computer. For example, consider an environment where user accounts are automatically removed from the server computer when they don't establish a connection with the server computer in a period greater than 7 days since the last valid connection established to the server computer. Once the user account is removed, it is no longer functional of course, and the person whom lost the account will need to create a new one, assuming it want to have access to the mail service again.