Most organization are using E-mail(electronic mail) currently, but we seldom see the organizational success from the E-mail utilization strategically. There are many research which are focusing on the selection and usage of E-mail as a electronic communication media based on Information Richness Theory and Critical Social Theory. The purpose of this study is to investigate the effects by using E-mail through providing the model of perceived impacts. This model considers the moderate factors such as top management supports, organizational usage, and organizational pressure based on CST. Also it provides the guideline how to use E-mail strategically.