This is no longer about hoax e-mails crying *wolf* spamming your e-mail inbox. This is a bona fide computer virus that has been making its rounds for the past few weeks. Here are two links where you can see for yourself that the danger is real:
http://www.snopes com/computer/virus/postcard.asp
http://vil.nai.com/vil/Content/v_142621.htm (McAfee)

Some of the subject lines have included:

• You’ve received a postcard from a worshipper!
• You’ve received an ecard from a admirer!
• You’ve received an ecard from a class mate!
• You’ve received an ecard from a colleague!
• You’ve received an ecard from a family member!
• You’ve received an ecard from a friend!
• You’ve received an ecard from a mate!
• You’ve received an ecard from a neighbour!
• You’ve received an ecard from a partner!
• You’ve received an ecard from a school friend!
• You’ve received an ecard from a school mate!
  
  
  When you click on the link in the e-mail, you are taken a website that will try and download malware, including trojan horses, onto your computer. The best thing to do is just delete the e-mail, even if you know the sender.

  (There was a hoax e-mail going around that was debunked by Snopes called "Virtual Card for You". Some of the virally-infected e-mails reference the hoax e-mail to get you to drop your guard--don't believe it--these are two different e-mails altogether.

  I've seen a large number of these myself (20-30 per week), although I am fortunate to have an on-the-ball ISP that virus-checks all incoming e-mail to their server, so they've caught almost all of them and let me know that the messages have been quarantined.

  Hopefully, none of you have clicked the links in any of those e-mails, but if you have, you can check out the McAfee link above for suggestions on removal.

  Good luck out there!