Faced with a rapidly ageing society and with constant technological progression, studies focused on fostering communicative action and reducing social isolation have become increasingly relevant. This paper presents a proposal of a graphical interface for an asynchronous communication service aimed at older adults, which was tested in different user contexts – both in Portugal and the United States of America. The main aims of this study are to determine to what extent the participation of older adults in the development of an email service can influence its usability and the design of a simplified interface. The usability results provide consistent clues as to how the technical development of an email service for older adults should proceed. We conclude that we should not design an email interface so as to be completely different from existing ones. Rather, we chose to improve its usability and simplify the entire process of using an email service.