Using the example of the exchange of an 'offensive' e-mail between a lecturer and a student at Auckland University, this paper argues that the inherent discursivity of evaluations of impoliteness in e-mail communication emerges not only from various perceptions of norms, but also from commentators' positioning towards these evaluations; the technological and situational features of the CMC medium in which these evaluations arise, mediates the relative level of discursive dispute.