Chinas Ministry of Information Industry has adopted the Measures for the Administration of Internet E-mails. The regulations, which took effect from 30 March 2006, are designed to apply to email service providers and apply to any person operating an email service for Internet users in Mainland China.
The regulations are as follows:
A provider is defined as any person in the service supply chain involved in delivering or helping users to receive email;
Service providers must register with the government and obtain a license before providing email services;
Violators face warnings or penalties of up to 30,000 yuan (approx. $3,700 US) and risk losing their license;
Firms are barred from sending unsolicited commercial messages without prior consent from recipients;
All commercial email must have a subject header of AD or the Chinese character for advertisement;
The rules only apply to email containing commercial advertisements;
The rules state that providers must stop delivery of any messages containing commercial advertisements even if a recipient first consents, but later changes his or her mind.
http://www.tid.gov.hk/english/aboutus/tradecircular/cic/asia/2006/files/ci200681a.pdf