I agree with sunnytheshine as it is clearly written on the NSNP guide that we need to send original nomination letter to CIC.
page 11 of 24
Nomination
You will receive from the Office of Immigration an email confirming that your nomination has been issued. You will receive by mail an original signed Letter of Nomination, plus a copy for your records. Please note: Your nomination expires 6 months after issuance; and when preparing your application package for submission to CIC, ensure that you include the original signed Letter of Nomination.