Despite workplace anxiety being a common experience of daily work life that is increasingly reliant on technology, we lack knowledge of technology-based job demands that prompt its occurrence. Drawing on theorization on workplace anxiety and integrating literature on information and communication technologies, we consider telepressure and normative response pressure as internal and external between-person sources of daily workplace anxiety. We further present a model of how employees adaptively (vs. maladaptively) respond to workplace anxiety on days they experience workplace anxiety, where anxiety prompts: (a) work e-mail activity, a self-regulatory behavior facilitating performance outcomes; and (b) non-work e-mail activity, a behavior that disengages employees from their work, debilitating performance outcomes. Utilizing a multilevel, time-lagged experience sampling field study across 10 workdays (Level 1 N = 809; Level 2 N = 96), we identify telepressure as a significant contributor of daily workplace anxiety. Further, we found support for an adaptive function of workplace anxiety. On days employees experienced workplace anxiety, their personal initiative and citizenship behaviors were enhanced through behavioral regulatory activity manifested in work e-mail activity. This indirect effect was strengthened for employees perceiving higher (vs. lower) work e-mail centrality. This research advances understanding of the adaptive function of workplace anxiety, such that employees are active drivers of their daily experiences of workplace anxiety.