• Use your spam filters. Nearly every free (and paid) email service has spam filters and junk boxes. If something goes to your junk mail, don't simply unblock it. Investigate the email, even if it looks like it's coming from someone you know. Make sure that it really did come from that person and that they intended to send it to you.
• Never click an unexpected link or download an unfamiliar attachment. Nearly all major companies (such as banks) have policies in place that require that if they need you to click a link to their site, they will include some sort of identifying information such as your name or last four digits of an account number. Pay special attention to that. Too many people see a generic email that simply says "Your account has been compromised, click here to validate." No legitimate bank or institution will ever send that. They would say "Dear Jason, We believe your account has been compromised, please call us at XXX-XXX-XXXX.