The purpose of this qualitative case study was to explore how the appraisal of email affected knowledge worker's perception of eustress and distress within a support organization that is a division of a large, publicly traded geospatial organization in the United States. The transactional model of stress and coping defines stress as a relationship between the environment and the individual that can result in either eustress or distress and has been applied to technostress research. It was not known how the appraisal of email affected knowledge worker's perception of eustress and distress. This study was guided by the following research questions: How does the appraisal of email affect the knowledge worker’s perception of eustress and distress? How do knowledge workers describe their appraisals of email demands that result in distress or in eustress? The sample of knowledge workers was chosen from the full-time knowledge workers whose work requires the use of computer-mediated communication within a large, publicly traded geospatial organization within the United States. Data was collected through interviews, questionnaire and focus groups of support people and their managers. The data was analyzed using thematic analysis resulting in some key themes such as having no control is related to distress appraisals while trust is related to eustress appraisals. The research suggests that by improving group dynamics, giving employees more control over their email management and training managers to be more aware of how management styles can cause eustress with email; organizations can improve technostress in the workplace.