As the E-mail server (gmail.com) we used before is not stable, even oddly unavailable in China, we switch to Chinese E-mail server (yeah.net). Please check our latest news Service Email Server Change for detail.

beijingesc(at)yeah.net : Service E-mail for Service Consulting and Communication.
davidyxf(at)gmail.com : Supervisor E-mail for Business Cooperation, Complaints and Claim.

Please replace (at) with @,

Sorry for any inconvenience.