Recently I was going through a article  somewhere  I read that over
the past several months, through processing billions of email
messages, many email users identified an increase in this particular
subset of spam, containing images only.

Traditional anti-spam technology -- such as content-based, Bayesian
filtering, Heuristics and URL filtering -- is practically defenseless
against this image-based spam, leaving organizations open to floods of
these types of email.

Spamjadoo is the only antispam product that actively discourages
spammers.Spamjadoo is available as software solution which can be
deployed on your desired servers or as Hardware Appliance , which can
be plugged into your network.