This paper provides a perspective on cultural differences in e-mail use of virtual teams from the critical social theory (CST) point of view. CST can be used as a qualitative methodology in information systems research. Among CST concepts, Habermas' theory of communicative action is applied here for the purpose of drawing a plausible explanation for the phenomenon of cultural differences between East Asian countries and the West in the use of e-mail in virtual teams. East Asian countries such as Korea and Japan, which are heavily influenced by the Confucius tradition of emphasizing respect for the social order in all forms of social communication activity, including e-mail, provide different type of patterns of e-mail use in management of virtual teams compared to Western countries such as the United States. Not only can CST provide adequate theoretical support for the claim that e-mail use can be varied due to cultural difference when it is used to manage virtual teams, but it can also identify cultural codes such as respect for seniors as a part of the complete information package that can be illuminated during the use of e-mail, by using a CST concept called "critical reflection." A real-life example of the experience of a Korean firm's virtual team in the use of e-mail is analyzed in order to illustrate the CST perspective on cultural differences in the use of e-mail for virtual teams.