While Hong Kong may have a reputation as a junk-mail haven, many experts believe China could be a new frontier for e-mail fraud and pyramid marketing. The number of indigenous spam businesses is still relatively small, but weak legislation, cultural differences and inexperience have made the mainland one of the most appealing for commercial junk mailers. 'I believe the problem about spams [in Hong Kong] is overblown,' said dots21 founder Charles Mok who sees China and Taiwan as far more serious spam sources. Scott Hazen Mueller, of San Francisco's Coalition Against Unsolicited Commercial E-mail (Cauce), said the majority of spam from China was sent by United States' firms exploiting insecure mail servers to relay their advertising. Programs such as the popular Sendmail often contain security holes hackers can open to gain control of a mail server, or enable mailers to disguise their origins by using an open mail server on which they have no account (known as third-party relay). 'With specific reference to the mainland, it appears mostly to be relay problems. I have seen some spam in Chinese, Japanese and Korean writing, but most of what I get from overseas is of US origin and in English,' Mr Mueller said. However, Alan Brown, administrator of New Zealand-based Orbs database, said mainland spammers were rapidly catching up with their US counterparts. 'It used to be the latter, but is rapidly becoming an issue of Chinese spammers - both direct, and hijacking other Chinese and Asian relays, particularly poorly secured ones, which are set to trust anything in Asia,' he said. Chinese University computer officer Fung Kin-ming said: 'I tend to think the mainland ISPs are like the wild, wild west. 'Many do not care to spend money on activities that do not generate revenues, and spam fighting takes a lot of resources.' Inexperience played an important role, Mr Mueller said. 'I suspect it is pretty much proportional to the age of the ISP,' he said. 'Since the mainland is still in the early stages of Internet penetration, I would guess the majority of ISPs there are not aware of the full range of the problem.' Mr Brown said Asian ISPs were slow to react to network problems because local network administrators tended to ignore issues. Mr Mueller said cultural differences and misunderstandings often exacerbated the problem. 'Asian administrators, in general, seem to react badly to foreigners telling them they have network problems,' he said. Many observers said mainland ISPs often dismissed spam as a foreign rather than domestic problem. 'It has got to be adding to the congestion of the mainland's very expensive international IP [Internet protocol] transit links,' Mr Mueller said. China's ISPs could easily alleviate the problem by simply disconnecting spammers, closing open relays and subscribing to black-hole lists. 'Ordinarily, I am opposed to censorship, but I will note that, if the operators of the Great Firewall of China were to use the various Maps systems, they could probably unilaterally cut the amount of spam relayed off mainland servers by 80 per cent to 90 per cent,' he said.