Can you imagine a world without email? While billions of people in the world don’t have an email address yet, chances are if you’re listening you do. Moreover you’ve probably had one for most of your life, or at least decades. If you have an email address, you’ve dealt with spam. Spam is almost as old as email, so how to stop it is one of the oldest problems in the Internet world. We’ll talk about how spam defenses for email delivery have evolved and the current standards.