If the email header doesn't say the mail originated from Blizzard's servers then it's a scam. You cannot fake that unless you actually send the mail from their servers.
http://dl.dropbox.com/u/12654979/realmail.png
http://dl.dropbox.com/u/12654979/fakemail.png
Edit:
Edited the post a bit. It came off as a bit too hostile than intended.