CSO have an article up explaining that annoying phenomenon of Image Spam, spam that evades filters by simply being an inline attached image file.|
But even as they block more messages, spam filters don?t get smarter as much as they get stronger. Their dictionaries of unacceptable traits grow, their IP blacklists get longer, and the processors that power them get more horses. But for the most part, filters don?t change what they do even if they can do more of it. However complex or strong, they still just parse text and HTML looking for spam.
Parsing an image, on the other hand, ain?t so easy.