The email text (at least the one we've seen) reads:
Hello!The file is "postcard.zip" which contains a file "postcard.exe". To nobody's surprise, postcard.exe isn't an e-card from a friend. There's something special about that e-card feeling. Boy, howdy.
You have recieved a Hallmark E-Card from your friend.
To see it, check the attachment.
There's something special about that E-Card feeling. We invite you to make a friend's day and send one.
Hope to see you soon,
Your friends at Hallmark
Your privacy is our priority. Click the "Privacy and Security" link at the bottom of this E-mail to view our policy.
Word to the wise: don't click this. Remember Borepatch's Law: "Free Download" is internet-speak for "open your mouth and close your eyes."
UPDATE 14 November 2008 18:34: Heh. Why thank you, Mr. I-Have-No-Idea-Who-You-Are! Yes, please, take my credit card number!