Asking about the attend to embassy with scan copy of invitation

Could you please help me for some information about needing to get the visa to China . We are employee SOC (South Oil company) in Iraq and we have official mission to visiting Factory in PRC (Factory Accepting Testing ) in 15.12.2015 but until now we don`t have invitation from the Factory or company and they promise us to send it by email (scan copy) . Is that acceptable or not or your embassy need the hard copy just? please inform us to let us visiting the embassy with scan copy .
I looking forward to receive your response as soon as possible .Many Thanks