I always used to wonder why there was an option, in many spam engines, to block out any mail coming from China (the country). It didn’t seem to me like that big a deal, and anyway stuff coming from Russia seemed far more suspect to start with. Until this past week. You see, it appears that Chinese ISPs filter outgoing mail and harvest outgoing email addresses, selling the address lists to spammers.
My brother moved to China recently and is teaching English there, and he’s been sending me email. Suddenly I became receiving Chinese-language spam. Lots of it. Now, Gmail has been very good at filtering that stuff out so I don’t have to deal with that spam directly (other than cleaning it out periodically), but those who don’t have as efficient an email provider should look out for this, because their inboxes will quickly become overwhelmed.
And to Chinese ISPs: shame on you for censoring, ratting on your users and harvesting email addresses for spam. It’s hardly a wonder that an increasing number of mail servers reject your traffic altogether.