Accidents caused by e-mail, such as information leaks from inside the company due to "Wrong Transmission e-mail" and cyber-attacks due to "Targeted Attack E-mail" from outside the company, are increasing day by day. How should we countermeasure to the e-mail threats that everybody uses everyday? In this seminar, we will explain the actual situations of loss caused by malware and damage of information leak caused by e-mail, and the most important point, we introduces countermeasure examples using the latest e-mail security.