NetEase Inc, China's largest e-mail service provider, is planning to launch a notary mail service in August in an attempt to stave off the challenge of social media services and increase its appeal to young Internet users.

The Nasdaq-listed Internet technology company has been making efforts to offer innovative value-added services to boost user loyalty.

The new service ensures all information that goes through the electronic mailboxes cannot be changed or deleted, in case users want to notarize e-mail information.

More and more users have requested original e-mail information for notary use, said Mo Zirui, deputy manager of NetEase's e-mail business unit.

"They need us to prove that they have got certain messages in e-mails," Mo said. "So to meet the increasing demand, we decided to offer notary mail service."

With a growing number of teenagers in China becoming mobile Internet users, the e-mail usage rate in the country has dropped significantly in recent years, according to Mo.

"It is critical for us to offer value-added services rather than simply supporting basic functions like receiving and sending e-mails," he said.

He said Chinese Internet users are preoccupied with social networking services, such as Tencent's QQ and WeChat.

The China Internet Development Statistical Report released in January by China Internet Network Information Center revealed e-mail is used by 92 percent of Internet users in the United States, and is the top application, while in China the figure is only 42 percent and e-mail is ranked 13th among Internet applications.

The report also stated 26 percent of China's Internet users are under 20 years old.

Through continuous innovation, NetEase's e-mail service users increased 18.2 percent to more than 650 million in the 12 months to March 2014. The majority of them use NetEase's free e-mail service and the company also offers charged e-mail services for its corporate and VIP users.

Xiao Yuyan, product manager of NetEase's notary mail service, said that the service is at the beta testing stage and only open to users who have been invited to take part.

"The feedback is beyond our expectation," Xiao said, adding that users have put the service to creative use.

"One user who works in media and publication said she can use the notary mail service for intellectual property rights protection," Xiao said. "Once she finishes an article, she can send an e-mail to herself and, if necessary, she can get information from our server to know exactly when she sent the e-mail in order to prove she is the first one to have the content."

The notary service is free to paid users of NetEase's e-mail service. Users who want to add the function to their free e-mail service will need to pay about 30 yuan ($4.84) a month.

Mo said the charged e-mail is not a high-profit service but basically helps the company to "break even".

"We don't want to make huge money out of the e-mail service but through offering the service, we want more people to use NetEase's news portal and to play our games," he said. "Generally speaking, we use e-mail as a gateway to reach out more to Internet users."