Information processing apparatus, communication system, and information processing method

An information processing apparatus includes a memory, a transmission unit, and a permission unit. The memory stores an identification of a client apparatus, a first mail address assigned to a first user, and first permission information indicating that the first user has authority to use a service, while associating the identification, the first mail address, and the first permission information with one another. The transmission unit transmits, in a case where the identification has been received from the client apparatus, a first email addressed to the first mail address stored in association with the identification that has been received. The permission unit permits, in a case where a reply corresponding to contents of the first email has been received from a terminal, use of the service in accordance with the first permission information stored in association with the first mail address.