Big flashing signs that an e-mail probably is a scam:

1)Payment must be through Western Union, MoneyGram or bank transfer only.

2) Nigeria. Sorry if this offends, but that is where a vast majority of the 419 variety scams come from. There are ways to track it to find out if you are unsure. They might claim to be from Europe or anywhere else, but until the IP is traced, you can't know for sure.

3) You won a lottery and didn't even enter it.

4) Cash the checks and send us the money. And keep XX% for your trouble. Could be for a part time job, or a payment for something you are selling. It doesn't matter. When the check bounces because it is fake, you have to pay it all back yourself. And you might get a visit from the police.

5) "100% risk free"

6) You must keep all of correspondance confidential until the transaction is complete.

A good rule of thumb is if it sounds too good to be true, it probably is. Think about it--why would someone from halfway around the world contact you to help them with an elementary situation, and offer you large amounts of money to do so. Those things just don't happen.