Electronic mail service, better known as e-mail, is probably the most widespread asynchronous way of exchanging data among people, thanks to its immediacy and easiness of use. In the framework of e-mail services, ensuring a valid identity has become a vital step in stopping spam, fraud and even more serious crimes; to this aim, Certified e-mail (CE) systems have been developed. Digital Terrestrial Television has introduced new communication facilities: the availability of commercial Set Top Boxes equipped with network interfaces and smart card readers makes it possible to manage user's identification and authentication, that are mandatory for the provisioning of T-government services, like CE. In this paper we discuss the challenges and opportunities of the CE service over Digital Terrestrial Television, and present the case study of the Italian Regione Marche, in which this service is implemented to support the remote request of certificates issued by the local Regional Administration. User authentication and secure access to the administrative services are addressed through the use of a regional service card (RSC), managed by means of a suited interactive application, and a centralized authentication framework.