My "main" email account, which I've had for over 10 years, is constantly deluged with spam. The host it's on supports "procmail", which is a mail-sorting and processing utility. I've used procmail to blackhole entire blocks of IP addresses. I think I must have most of China blocked by now.

As for why so much spam comes out of China, I obviously have no idea, but I do have a few theories. One of them has to do with the Chinese penchant for pirating software, on all levels, not just for home use but for business, telecommunications and government use, too. To continue this theory, this would mean that there were an awful lot of unpatched, vulnerable Windows operating systems out there, on machines which are left on 24 hours a day, easy prey to the organized thieves (such as the rings in Russia, Romania and probably a few other places starting either with "R" or other letters:-) who build zombie networks to use for remote spam and phishing attacks.

Anyway, I made a judgement call. Am I worried about missing mail from someone in China? I decided if I couldn't think of another way to screen out all the spam, I'd just have to risk it.