1. Does it say, "Send this to everyone you know" or similar?
2. Does it use technical sounding language or jargon and everything will crumble if you ignore the advice?
3. Does it imply credibility by association, meaning it somehow seems to come from a reliable or official source such as Microsoft, Citibank, Symantec, etc?

If it fits into any or all of these criteria, then it is probably a hoax!

What about chain letters?

Chain letters are essentially a hoax... a good old fashioned con, but using an electronic medium which brings with it a host of other security issues. Just like the good old fashioned variety chain letter, there is a "hook" which grabs your attention, eg; dying little girl, get rich quick, free money, blah, blah, blah.

Then there is the "threat" which warns you of the terrible things that will happen to you if you don't continue the chain. And of course you have to pass it on to as many people as you know!

What do I do?

1. Whatever you do, DO NOT forward it to everyone. At best you are spamming which is inconsiderate and illegal. At worst, you may infect your computer or even someone else's with some sort of Malaware and this could be disastrous.
2. If it looks like it comes from an official source don't bother to email them. Most hoax/chain letters don't have any contact information and if they do it's probably fake. You, along with a few million other recipients probably have the same idea and end up bombarding their servers. This amounts to a DOS (Denial Of Service Attack) which is not very nice.
3. If you're really curious, go to your Antivirus Vendor's website and see if it's listed there. If not, check out these sites. Chances are you will find it listed somewhere.

CHECK FOR HOAXES HERE...