Systems and methods for an anti-spam detection module that can detect image spam are provided. According to one embodiment, an image spam detection process involves determining and measuring various characteristics of images that may be embedded within or otherwise associated with an electronic mail (email) message. An approximate display location of the embedded images is determined. The existence of one or more abnormal factors associated with the embedded images is identified. A quantity of text included in the one or more embedded images is determined and measured by analyzing one or more blocks of binarized representations of the one or more embedded images. Finally, the likelihood that the email message is spam is determined based on one or more of the approximate display location, the existence of one or more abnormal factors and the quantity and location of text measured.