The majority of my spam recently has involved stock recommendations encoded as an embedded GIF. Examples of some less grammatically-challenged subject lines are: “garbage can Frisbee”, “official espresso”, “noisy symmetry”, “crutch innuendo”, “fabricate hiccup” and “depraved give-and-take”.
Today I received an e-mail that illustrates how spammers are adopting image manipulation techniques used in captchas to encode their images.
I think this is interesting as the spammers are using a technique that has previously been deployed against them (to hinder automated sign-up for free e-mail accounts and blog comment spam, for example).
Personally, I use the Qurb white list e-mail filter which does a good job of catching these messages.