Is the document for you?
This is a simple check to see if MS documents sent to you are original.
Click the 'File' tab
Click on 'Properties'
Now you will see a summary of when the document you are reading was created.
Often I find documents sent to me have people I've never heard of as the author and / or the document is named something else (as in it's been reincarnated).
Of course, if you know this trick, you can change the properties to reflect other information before sending out.