I'v experienced the same thing -- lots more spam, mostly penny stock stuff with inline images. The first thing I did was look at the email source, and write a regex on the single-image include and put that as a email-blocking test on my spam filter, http://assp.sourceforge.net/ ASSP this quickly put virtually all of these spams into the blacklist of the filter; after a week I turned the regex off and ASSP has been blocking it since. I agree with some of the other posters, however, if this gets escalated again where the filters start becoming useless, I'll go 100% whitelist here.