November 14, 2004

Although it is technically possible to deliver an image with the message, it is much more efficient to compose the message like a Web page, including the HTML codes that Web pages use to download images to a Web browser. The HTML code is very compact, meaning that spammers can blast more messages per minute than if the message actually contained an image.

Fortunately for spammers, most email users these days run email programs (like numerous variations of Microsoft's Outlook), which welcome messages sent in the form of Web pages. That's exactly what the spammers count on when they include codes that download images (and sometimes more nefarious things) when you preview or view the message.

Unfortunately for users, the code that retrieves an image can also identify your email address as being "live" when it retrieves the image. The email address of the recipient had been appended to the address (URL) of the image, and the spammer's Web server tracks that info when your email program fetches the image.

By confirming your email address to the spammer, you've contributed to the spam economy. Your address will now be further sold and traded among spammers, ensuring a future loaded with even more spam.