Lots of interesting nuggets in here:
Their research showed about 15% of our total spam email originates from IP addresses in China. However, it may actually originate elsewhere, as spammers use tactics to disguise their identity and location. China is probably not the “true” originator of the spam – much of it is sent by US or other spammers who use Chinese Web hosting. In the United States, there are equal parts of good and spam email. Very little spam comes from Japan.
The researchers found out that the international language of spam is English. Spammers send more emails in English than any other language. Email users rarely see spam messages in Korean or Japanese, though they are seeing increasing volumes of non-English spam.
99,999 Innocent Bystanders Spammed [research.microsoft.com]