Create a design for a secure email infrastructure. You can choose any email system, server, client, and security appliance or software you know about or can find information about from any appropriate source. Your design may be real or notional. It may include components that exist or that are only a figment of your imagination. The only rule about using any component is you must explain how it contributes to the security of your email system and what, if any, drawbacks or limitations it has. Produce a Visio diagram of your logical infrastructure and a 1 page Executive Summary that explains the major components, their functions, and capabilities/limitations. Include protection against spam and phishing emails in your infrastructure.