What a lovely surprise, a 'classmate' has sent you an electronic greeting card! How nice.
The only thing is, that "greeting card" may just be hiding nasty little computer viruses that could harm your computer, or spyware that resides on your computer and allows other people to access it without your knowledge.
Some of these bogus e-cards appear to come from the "Greeting Card Association," a real trade group which DOES NOT issue greeting cards, or other legitimate-sounding companies. Often the email's subject line says a "a former classmate" or "a family member" has sent a greeting card.