Application requirements for entry to China

Hello from Australia

We are organising a golfing tour on behalf of our clients in Kiev. My client says that the embassy in Kiev required a posted signed document of invitation. My wholesaler has sent the invitation letter by email with a confirmation of the hotel booking and itinerary for the client with her name and passport on it. If this is printed in Ukraine will this meet the requirements of the Chinese Embassy. My client believe that this needs to be signed and posted. This is a very big headache!