Scores of companies in Beijing were unable to send or receive e-mail from outside China for several days last month because a junk mailer using the same Internet service provider (ISP) landed them all on the same blacklist. The block on about 100 Internet protocol (IP) addresses has inconvenienced at least the same number of businesses since the middle of last month. This has led one of the victims to call it the worst disruption to e-mail services he has seen in China. 'What we have now is actually not just the one incident, but a whole mesh of interrelated ISPs around Asia that are being affected,' said Danny Levinson, chief operating officer of an affected online games company. The blockage is the latest in a series of disruptions that have drawn attention to the issue of junk mail in China. Many overseas anti-spam pressure groups say that junk mailers who find themselves unable to operate in the United States or in Europe are increasingly turning to the less-regulated mainland market for a safe haven. However, Mr Levinson doubted the effectiveness of blockades in stopping spam. 'There is no one root cause. It is like trying to put a Band-Aid on a lava flow.' The latest problem started when SPEWS.org, an organisation that circulates spammer blacklists to ISPs around the world, added two mass message services to its lists - Cayman Islands-registered Seekercenter. net and Trafficmagnet.net - according to the February 21 issue of e-mail newsletter China Internet Update. Capitalnet.com.cn and A-1.net, both from China, provided hosting services to the Seekcenter and Trafficmagnet Web sites. Because e-mail sent through Capitalnet can shift IP addresses, it is hard for organisations that track spammers to know exactly which company is sending unwelcome mass e-mails, so SPEWS recommended cutting off a block of IP addresses. However, these addresses often route the e-mail of companies that do not send spam. China Internet Update said in an editorial: 'SPEWS has no alternative but to block dozens or hundreds of innocent sites. This problem must stop. Companies like Capitalnet.com.cn must be held accountable for not doing anything about the customers using their services.' Cross-border e-mail blockades are not new to China. Last year, Hong Kong's Netvigator was threatened with a block of its users for allowing spam, and three major ISPs in the US blocked China e-mail because of spam. 'The widespread perception is that Chinese administrators do not take sufficient action against spammers, hackers or non-secure or hacked servers on their network,' said Suresh Ramasubramanian,messaging systems specialist at Hong Kong Internet solutions firm Outblaze. 'Some social pundits, or armchair theorists, also have a theory that for an Asian administrator to admit that he has done something wrong, and is not able to control spam or hacking from his network, amounts to a loss of face for him,' Mr Ramasubramanian said. One Beijing company affected was Mr Levinson's firm Moxze, which offers an online game called Zhanshen. Mr Levinson said Moxze could not send many of its 60,000 players confirmation codes because the game's host blocked the game's Capitalnet e-mail IP addresses. His staff had been inundated with complaints from users. A Capitalnet spokeswoman in Beijing said she had heard about the e-mail blacklists but her company could not stop them. It was each client's responsibility to use the Internet wisely, she said. 'How they use it is their matter,' she said. The Beijing office of a public relations company was also hit. The office vice-president said that, starting on February 15, he and his staff of 20 could not see the 30 to 40 e-mails they normally receive in a day. When they tried to send e-mail, it would either pause for a long time or fail. The company flew in a Hong Kong technical expert, who spent 16 hours making phone calls to the company's US headquarters and Microsoft to solve the problem. The problem lasted for four days during the Lunar New Year holiday week, the vice-president said, so business losses were minimal. The public relations company, after discussing the issue with other Beijing firms, called in three representatives of Capitalnet. The company did not admit to causing any problems, the vice-president said, but later sent a letter apologising for the quality of its service. Capitalnet had also worked with Moxze to fix Moxze's problem, Mr Levinson said.