E-mail address for submitting documents

My wife (a Chinese citizen) and I have been invited to her niece's wedding in China. I have submitted an application along with my passport. I received a phone call requesting a signed copy of the invitation plus my niece's Chinese National I.D. card front and back. I have tried several times to e-mail these documents but each time it has failed. Can you tell me the correct e-mail address I should send them to? Kind Regards, William Thornton.