Information Richness Theory (IRT) has enjoyed acceptance by information systems researchers throughout the last decade, but recent unfavorable empirical evidence has precipitated a shift away from it and a search for a new theory. Because of this shift, a new definition of communication richness is needed to succeed the IRT definition. Since its inception, IS research on communication richness has been limited to the perspective of positivism and, more recently, interpretivism. In this study, a new perspective to the study of communication richness in computer mediated communication, critical social theory (CST), is introduced. The paper outlines (1) a CST-based definition of communication richness and compares it with positivist and interpretivist definitions of communication richness and (2) a CST-based social action framework for empirical study of organizational communication in any media use situation. The CST definition and framework are used in an intensive investigation of an episode of the managerial use of electronic mail in a company to illustrate how research on communication richness can be conducted from the CST perspective. This illustration also points cut the usefulness of the CST perspective in recognizing instances of communication richness in electronic mail communications that would escape detection in not just the IRT perspective in particular, but also positivist and interpretive perspectives in general. Finally, the paper concludes by outlining the potential for future IS research on organizational communication and information technology from the CST perspective. In addition to the specific contribution to the development of a new theory of communication richness in electronic media, this study also contributes an example of CST research on IS and extends the domain of the CST-IS research program.