Messaging apps such as WhatsApp collapse temporal and spatial distances and enable continuous interactions. At the same time, messaging apps blur boundaries by default and contribute to the blending of different relational contexts as well as the collapsing of absence and presence. Whereas existing studies have mainly focused on the blurring of boundaries between work and private life, this study expands beyond the personal/professional binary and considers boundary work in more nuanced relational contexts. In order to provide a better understanding of boundary work within messaging practices, we conducted interviews and focus groups with employees from a variety of Dutch workplaces, and with participants of WhatsApp neighborhood crime prevention groups. Our findings highlight two forms of boundary work strategies. First, respondents purposefully tinker with WhatsApp features to manage the boundaries between absence and presence. Second, they use smartphone and WhatsApp functionalities to carefully construct segmentations between different contexts. The meaning of particular contexts, the materiality of messaging apps, and technical know-how play a crucial role in these boundary-sculpting practices. The importance of our study is in noting how the ongoing contradictions of messaging practices—being always available but always negotiating that availability—affect everyday experiences of freedom, privacy, and autonomy in significant ways.