Instructors and trainers are increasingly using online education and technology-mediated learning (TML) to supplement or replace traditional approaches to classroom teaching. Because mandatory involvement requirements may not intrinsically motivate learners to achieve high quality learning, social factors with commitment, such as identification among group members, are especially important determinants of TML success. This article investigates an individual's social and self identities as important determinants in developing affective commitment (identification) and intrinsic motivation (perceived enjoyment) to share knowledge by email in the TML environment. Furthermore, given the recent emphasis on gender in system adoption and socio-linguistic literature, this study investigates gender as a moderating variable in the proposed model. An empirical test of the proposed model was conducted in the pilot test (n = 155) as well as the main test (n = 411). Social and self identities influence identification (R[superscript 2] = 0.42) and perceived enjoyment (R[superscript 2] = 0.52) of sharing knowledge by email. As expected, there are significant moderating effects of gender in these relationships in that male shows stronger effects of self identity while female shows stronger effects of social identity. The results of this study will help us understand the antecedents of effective knowledge sharing intervention in the TML environment, based on the integrated model of social identity theory, social influence theory, self determination theory and socio-linguistic literature. (Contains 5 notes, 4 tables, and 2 figures.)