Forward the email (without changing anything, not even the header) to 
spoof@ebay.com.  I do this with every fake looking email I receive from Ebay.  That way, Ebay can keep a record of the fake emails floating around.  Someone will usually email you back within a few minutes to let you know if it is legit or not.  Also, you can always check the Ebay Security Center to double-check on anything that might look funky.