This research investigated how customer service employees’ positive and negative emotions affect their task performance and contribute to the success of the organizations. The author conveyed a survey and distributed approximately a total of 1,000 five-point Likert typed questionnaires to flight attendants working for a European airline as well as an Asian airline and received 827 valid responses. The author presented the descriptive statistics and then examined some relationships using the structural equation model to test the hypotheses. The findings include that affective delivery, which refers to an act of expressing socially desired emotions, functions as a mediator, converting the negative path coefficient between role conflicts and job performance to a positive one. In conclusion, employees’ display of positive emotions functions as a mediator even in workplaces, where role conflict may be perceived. Therefore, the practice of positive emotion to recover the declining propensity of task performance prevent employees from the risk of emotional exhaustion, promote customer satisfaction, and contribute to gain customer loyalty.