The email seems to be a hoax, just a variant on an older hoax?:
I regularly get 'postcard'/'ecard' emails and just delete them
This particular email is a hoax---although there has been a real "Postcard" virus.
The hoax has circulated continuously on the Internet since at least 2001.
There is no known virus called "A card for you" or "A virtual card for you."
In July, 2007, someone added "Postcard" to the story and said that it had been verified as a true virus.
Note: It is true that there was a virus that appeared in the summer of 2007 with a subject line of: "You've received a postcard from a family member." There were several other variations of the subject line that talked about a "card" or a "greeting card." But that virus had nothing to do with this false warning about "A card for you" or "A virtual card for you" and the warning that CNN had termed it the worst virus ever.
Microsoft, Norton, or McAfee have had nothing to say about it except that it is a hoax.
The CNN part of the eRumor was added by someone along the way.
In June, 2008, someone added that the message in the virus was "POSTCARD FROM HALLMARK," which is also untrue.