From the savvy teenager to the Board room executive, awareness rules. You've probably already heard the mantra: Don't open emails from unknown or unsolicited sources. And when you receive an email from an unknown source, don't let down your guard; cyber criminals use email addresses in your email address book as one social engineering technique. A teenager receives an email from a friend about an event he saw on the news today, and it looks legitimate. An executive receives an email about a corporate financial review, and it too looks legitimate.