Spam Filter E-mail - Email Spam Filter

Image spam is an obfuscating method in which the text of the message is stored as a GIF or JPEG image and displayed in the email. This prevents text based spam filters from detecting and blocking spam messages. Image spam is currently used largely to advertise "pump and dump" stocks.[100]

Often, image spam contains nonsensical, computer-generated text which simply annoys the reader. However, new technology in some programs try to read the images by attempting to find text in these images. They are not very accurate, and sometimes filter out innocent images of products like a box that has words on it.

A newer technique, however, is to use an animated GIF image that does not contain clear text in its initial frame, or to contort the shapes of letters in the image (as in CAPTCHA) to avoid detection by OCR tools.