Email: The Difference Between Junk and Spam

Bob Young
5 min readMay 30, 2019

Junk email and spam email aren’t the same, and you should treat them differently. Here’s everything you need to know.

First, a brief disclaimer… Although there’s a technical difference between junk email and spam email, most people use the terms interchangeably. Also, some email programs don’t make a clear distinction. One email program lets you mark email as “junk.”

Another email program lets you mark email as “spam.”

And yet another email program lets you choose whether to mark an email as “spam” or “junk.”

In this article I’m going to explain the technical difference between spam and junk, but your email program may not let you take advantage of this information.


Let’s start with the paper, “snail mail” equivalent, and consider junk mail. Suppose that you’re old enough to be a member of AARP, and you decide to join. Periodically, AARP will send you special offers in the mail: discounted vacations, life insurance, cell phone deals, and so forth. These are legitimate offers. If you pay money for the cruise to the Bahamas, you’ll actually get to take a cruise to the Bahamas. But if you’re not interested, you call it “junk mail” and throw it in the wastebasket.

Junk email is the electronic equivalent to paper junk mail. Junk email is legitimate offers from real companies. You may not want it, and you may find it annoying, but it’s not illegal or fraudulent.


Spam email is sent out by criminals with the intent to steal your money, your personal information, or both. One well-known example of this type of email is called the “Nigerian Prince” scam. Another common example are the many emails from fake pharmaceutical companies, offering expensive medicines at deeply discounted prices. If you place an order and give them your credit card number, you may not receive anything at all — or you may receive a package containing fake pills with no medicinal value. The way criminal spammers make money is by taking advantage of the sheer volume of emails they send out. If they send an email advertising medicine to ten thousand email addresses, and only one person in a thousand places an order, they’ve collected credit card information for ten people — and they may use each credit card for hundreds or thousands of dollars worth of goods or cash advances!

Bob Young

CISO, Director of Information Security, and Security Consultant. Also, I wrote some books that have nothing to do with IT.