E-mail is an indispensable communication tool in the modern enterprise organizes. E-mail is also so prominent for these teams that they communicate via e-mail daily, and is the main media for asynchronous meetings. This study explores the suitability of using e-mail to support group decision making. In order to reduce the communication obstacle which the group may encounter while using the asynchronous communication of E-mail, this study proposes two group techniques suitable for E-mail–Nominal Group Technique (NGT) and Round-Robin NGT. This study also explores the effectiveness of E-mail-mediated group supported by the structured group techniques and which type of task suitable for E-mail-mediated group. An experiment involving a total of 150 undergraduates was conducted. Results show that group techniques used in this study appears to be useful for facilitating E-mail-mediated group. But task type had no significant influence on E-mail-mediated group