> Check out the interesting idea at www.rulesemporium.com/forums/ > > entitled: Image attachment MD5 footprint RBL
My only comment on a system like this is that it could be easily subverted. A spammer could use automated image editting tools to randomly change some aspect of the file that would give it a totally different MD5 sum. Like changing the lower right pixel to a different color would throw the md5 sum way off.
