There is a great deal more email spam in your inboxes this Autumn (as noted, for example, here, here and here!). That’s partly because a very great deal more spam is being generated — perhaps twice as much as just a few months ago.
A lot of this junk is “image spam”, where the advertisement is contained within an embedded picture (almost invariably a GIF file). The filtering systems that almost everyone now uses are having significant problems in dealing with these images and so a higher percentage of the spam that arrives at the filters is getting through to your inbox.
So higher volumes and weaker filtering are combining to cause a significant problem for us all 
But I have an interesting suggestion for filtering the images: it might be a lot simpler to go about it backwards 
So read on!