What happens when an organization provides employees a technology that enables constant connectivity to email? How and why do some groups manage the potential for connectivity in a way that increases flexibility on the job and personal 'free' time, while others create expectations of expanded accessibility to work? A three-year qualitative study of the enactment of mobile email devices in a footwear manufacturer provides empirical grounding to address these questions. Focusing on the experience of two occupational functions, this research argues that congruent frames of heterogeneous communication practices enabled one group to develop communication norms that circumvented the trap of constant connectivity, while assumptions of homogeneous communication practices in the other group led to expanded accessibility and erosion of personal time. This study examines how such alternate trajectories of use emerged and discusses the key dimensions of difference between groups - identity, materiality, vulnerability and visibility - that help account for these differences. In introducing the distinction between homogeneous and heterogeneous trajectories of use, and explicating how such trajectories emerge, this paper offers several theoretical insights: it suggests that there is a distinction between the congruence of technological frames of reference and the content of these frames; it provides an explanation for why groups might enact mobile communication technologies in a manner that does not lead to constant connectivity; and it highlights how shared assumptions of heterogeneity relate to systems of social control.