Email is a ubiquitous and work-critical tool for many people at work today. Research suggests that people engage a range of actions to deal with work-email, with the same email action (e.g. turning off email) facilitating some goals (e.g. for well-being) but hindering others (e.g. for being helpful). Using mixed-methods across two studies with knowledge workers who use work-email, we examined whether individual differences in personality can explain why there is a goal paradox of work-email actions. The theory of purposeful work behavior (TPWB) informs our approach. In Study 1, semi-structured interviews (N = 28) uncovered (using thematic analysis) a comprehensive list of 72 work-email actions that differently impact goals related to Work, Well-being, Control and Concern. Study 2 then addressed whether personality traits could predict work-email activity directed towards these four goals. A multi-level survey (N = 341; n = 5575) of work-email activity was analyzed using cross-level hierarchical linear modelling. We found that action-goal relationships in dealing with work-email, could be predicted by people’s trait-relevant goal striving. This advances understanding of why work-email actions can be both beneficial and problematic for people. Use of habitual actions also interacted with personality to strengthen action-goal relationships, except for those with low Emotional Stability. Findings are discussed in terms of their implications for theory, policy and practice.