You work as a Network Administrator for Blue Well Inc. The company has a Windows Server 2008 domain-based network. All client computers on the network run Windows Vista Ultimate. Andy, a Finance Manager, uses Windows Mail to download his e-mails to his inbox. He complains that every now and then he gets mails asking for revealing personal or financial information. He wants that such mails are not shown to him. Which of the following steps will you take to accomplish the task?