You're an idiot for taking the word of a complete stranger that they've checked Snopes. They haven't. http://www.snopes.com/computer/virus/postcard.asp
(found by googling "snopes postcard hallmark" which isn't exactly a difficult search string to think up)
Also an obvious fake for the following reasons:
- threatens really bad things
- demands you send the email to all your contacts (so it's a chain letter)
- no reference URLs - it just refers to CNN, Snopes etc for pretend authenticity.
ALWAYS check references before sending stuff like this. Anything that demands you send it to all your contacts IS a chain letter and IS NOT worth forwarding - this is what bungs up the internet for everyone!