Amid the increasing digitisation of schools, relatively little work has examined the ways in which digital technologies are reconfiguring the work of school principals. With an approach based on the sociology of work, this paper draws on 19 in-depth interviews with Australian school principals to examine their everyday experiences of digital work--with particular attention paid to the enduring influence of email as a key work tool. On one hand, email was seen as a constant and unremarkable feature of 'modern' school leadership. Yet, these accounts also highlighted how the intensification and extension of individual principals' labour practices were being exacerbated by multiple layers and technologies of surveillance, expectations of constant availability, and increased accountabilities imposed through email. Of particular significance were the detrimental ways in which email-based work was described as reshaping the affective dimensions of principals' work. Against this background, the paper considers what steps might be taken to mitigate such pressures, and perhaps move towards alternate forms of digitally-supported work that are more sustainable.