For some customers, their user environment may not have an outside internet connection or for security reasons, they prefer to be able to execute Mail & Deploy fully on-premise.
So, Mail & Deploy can work offline. In case Mail & Deploy has to distribute reports outside the organization, Mail & Deploy would need connectivity, for example, to an FTP server or an SMTP server.
When you are installing the offline mode of Mail & Deploy, the option for automatic updates will disappear. It is in your own responsibility to regularly check for the latest version, updates, and releases.