If you receive an email entitled You've received a postcard from a family member! it is not safe. Do not click on any links in the email - it is a disguised link to another server or PC. (This is a trick similar to many phishing e-mails.) However, the page consists of several exploits that affects Internet Explorer.
Here is the typical wording for this hoax message:
You've received a postcard from a family member!
Your family member has sent you an ecard from onleak.hk.
Send free ecards from onleak.hk with your choice of colors, words and music.
Your ecard will be available with us for the next 30 days. If you wish to keep the ecard longer, you may save it on your computer or take a print.
To view your ecard, choose from any of the following options:
Click on the following Internet address or copy & paste it into your browser's address box.
Copy & paste the ecard number in the "View Your Card" box at http://some-randomly-madeup-address
Your ecard number is
*If you would like to send someone an ecard, you can do so at http://some-randomly-madeup-address