In order to prevent hackers and to block email spam, Chongqing Telecom has started a dynamic IP address reverse lookup service in the city.

IP address reverse lookup means that the server carries out a reverse analysis on the IP addresses which are displayed in emails and refuses those emails whose IP address doesn't have a corresponding licensed domain name. This is said to be effective for preventing hackers and cleanses the overall network environment. Similar systems have been developed by Yahoo, AOL, and Microsoft overseas.

Chongqing Telecom says that it has initiated this service to meet the fast growing demand from broadband users and to expand its Internet applications.

According to international anti-spam group Spamhaus, China still ranks second in the world as the source of most email spam. On top of that, Chongqing Telecom has in the past also been a place that has harbored international spam gangs.