Does Original Invitation Letter needed for apply Visa ?

Dear Sir,

I'm Madusha from Tajima Colombo (Pte) Ltd. We are planing to visit Shanghai Tex Exhibition. So we need to apply Visa. We have received Invitation letter through e-mail. I just want to know whether you want original Invitation Letter to issue a Visa.

Please kindly let us know.

Rgds
madusha