A service provision system includes: a management information storage unit that stores management information for managing user identification information, device identification information, and service identification information in association with one another; an authentication information receiving unit that receives authentication information including user authentication information and device authentication information from a device connected via a network; a service specifying unit that specifies, when the authentication information is authenticated by an authentication unit, a service associated with the authentication information based on the authentication information and the management information; and a first execution unit that receives a use request of a mail distribution service from the first device connected via the network, composes a mail according to the use request of the mail distribution service received from the first device, and distributes the composed mail to a previously specified mail server connected to the service provision system via a network.