Simple and effective inline image spam fighting method

So, the spammers have been sending you new spam in the form of inline images.
I have a web background which facilitated a way around these lousy attempts to clog my inbox. If you attempt to figure out what the name of the image is - you are led to believe that it's 'untitled.bmp' - and you can build a filter to block that, but it doesn't work (because that's not really the name of the image - it's actually encrypted). Upon closer examination of several inline image emails that I had received, I found a common character set that could be used to filter by.

Here it is: "cid:"
Build yourself a filter in whatever your email client may be... find this string and do whatever action it is you prefer. While testing, I had it append the message title to let me know that it worked, later I changed the action to 'delete' the message completely. This method should be fairly safe for most of your email unless of course you get emails full of these encrypted inline images from your peers. You might lose an email if you were say talking about things that are
rancid: or placid: but how often would they be followed by a colon? Best of luck!