Updated at 6.47pm: Chinese Internet portal Sina.com will have to appear in a Beijing district court to answer accusations that it breached a contract agreement by drastically cutting the size of its free e-mail service on September 16. In August, Sina.com caused an uproar all over the mainland when it announced it would take a whopping bite out of its individual free e-mail service, trimming it from 50 megabytes to 5MB, while beginning a paid e-mail service that was supposed to be more personalised and reliable. That decision did not sit well with a large segment of the public. And on Thursday, Tianjin-based lawyer Lai Yunpeng filed a lawsuit with the Haidian District Court in Beijing. A court date has not yet been set, but Mr Lai said the court was likely to look at the case in about three weeks. Analysts say this is the mainland's first legal wrangle over e-mail services and that it could give rise to an avalanche of cases against e-mail service providers who back away from promised free Internet services. Providers use the offer of free services to attract customers who, in turn, attract online ads, but then the provider sometimes quietly withdraws the free services. A district court judge, whose name was given only as Kuo, told Xinhua News Agency on Thursday that Sina.com did renege on its free-service promise, but he refused to say whether it was a breach of contract. He said the court would tread extra carefully because the case had no precedent in mainland China. But the lawyer-plaintiff, Mr Lai, said that the terms of service that were stated online, and which users agreed to when registering for Sina.com's e-mail service, were clearly a contract of some kind between the user and Sina.com, therefore Sina.com was in breach of contract by changing its services without consulting the customers. Mr Lai also dismissed the widely accepted idea that so-called free e-mail services were actually free. He said users should think about what they did after they enjoyed the 'free lunch'. 'Every time we send an e-mail, we deliver a commercial message on behalf of Sina.com within our own connection and our networks. And after that you still think that service is free?' This relationship between service provider and user, he said, was a typical contractual agreement. He also said it was unfair to customers that Sina.com had inserted the clause, 'we reserve the right to change or terminate service without informing the user and are not responsible for any effects a change or service cancellation may cause any person'. In fact, that clause was a violation of China's Contract Law, he said. Mr Lai said he was demanding that Sina.com restore his 50MB e-mail box and pay all legal expenses to be incurred. 'I have no problem with their wanting to make money, but they need to learn how to maintain their creditability and reputation,' he said. Sina.com has 25 million people using its e-mail services, about 2 per cent of whom have used their 5MB capacity, according to Sina.com's own figures.