Use email2 in countries that control e-mail like China?

Yes!

Many of our current customers and users have confirmed that email2 messages are successfully delivered to Chinese recipients. Because email2 messages are exchanged across HTTPS connections, typical filters for basic e-mail does not affect them. If a potential recipient can reach the email2 Web Client for a Private Email Network, he or she will be able to read email2 messages.

//Edited December 2009