is this e-mail Legit?

As others have said, the email is legit. If you're still in doubt, I'll throw in my personal experience as well: When I won, einquiry.nexon.net sent me an email as well and I replied to it and got my Dell XPS from them with no difficulty. As Alysha's said, they dont follow their own rules or whatever you want to call it when they say "a game master will never ask for your info, etc. etc. etc" I guess einquiry isnt considered a game master, heh.

Congratz on winning~

Edit: @ Acim: I think the point is to give the info that you won on, meaning its a way to verify that it is indeed your account that won. Giving a mule's login id would defeat the purpose of that entirely >_>