If you DO get one direct from Nigeria, which hasn't been through GN, then www.fraudaid.com/find_headers.htm says ^"find the Full Headers (aka Message Source, Details, Internet Path, Origin, Original Message, Properties, Options, Email Message Source) which show the entire path an email traveled from the author's computer to yours. It is at least 2" to 3" long. When we track an email, we work back down the path to the author's computer. "
^Without the Full Headers, it's impossible to report Spam or scam email to anyone since the Brief Headers (just the From, To, Date, and Subject lines) don't provide any information that can be used to find out where the malicious email came from^"
If you have Firefox the full headers are in the message source, - you will find "message source" under the "view" button