Yes, definitely not "authentic". Chinese knockoff. Folks at work order all the time, hundreds of jerseys ordered over the last few years, from Chinese knockoff places, but not this particular one.
Orders from coworkers have been stopped at customs a few times, but they've always been refunded when they were.
Authentic, no. Very good knockoffs, yes. The quality of the knockoffs you would never know they weren't authentic. Shady though buying knockoffs, but then again, the hockey jerseys that everyone around me usually buys aren't exactly worth the $300 you would pay for authentic. If they want to stop the illegal knockoffs, perhaps not charging an arm and a leg just because it says NHL or Reebok (the hockey jerseys anyways) on it.