Bottled over 5 years ago, and stored/shipped in unknown conditions - prime example of why Creed in the grey market is almost just as unpredictable as Creed on Ebay. None of the favorite (read "cheaper than retail") online sites claim that their versions are "fresh". If anything at all, they only claim that their stock is the real thing (which in your case, is most likely true).
I, myself, almost acquired 3 16.7oz of MI from an online retailer, but resisted due to this "roll of the dice"-nature of online purchases.
I'm not sure what their return policy is, but it may, in fact, be worthwhile to pursue/investigate in your particular situation. For example, if they claim a 20% restocking fee, it still may be a good deal (who wants any Creed that has lost critical notes?).
Good luck and keep us informed of your decision and possible interaction w/ this retailer.