The domain settings group all information that is not specific to any particular user or to any particular service.
General Settings: This section gathers settings such as the name of the organization and the choice of a locale. It also contains the activation of advanced features of the console and of an SSL connection for all domain users.
Settings related to the account: This contains a link to buy more accounts and information for contacting the administrator.
Names of the domain: This allows adding aliases to the domain name. This is useful, for instance, to allow users to use more than one address to receive their mail.