You may have noticed a lot of email purporting to come from MSNBC.com in the last few weeks and this is a result of a new spam campaign doing the rounds. Problem is that some of these headlines could actually be valid; even if people are intelligently looking at their email for spam, they might miss one or two of these. Have a look here to see how many you think could be valid.
So the trick is to look at the email as whole, including headers and attachments, if there is any doubt at all. For example, why would MSNBC.com be sending you email in the first place?