ncsoft is a well-known and respected maker of popular MMO games. They are not the spammer.
However, I may have a better idea of what is going on, because my own email account just got hit with exactly the same problem. Your email password: how secure is it? Does it contain letters and numbers both? Is it a word that's in the dictionary?
My own email account has been sending a huge quantity of spam lately. As it turns out, there is a spam group in the Ukraine that has over the past couple of weeks launched an extremely aggressive password-cracking campaign. They collect millions of email addresses and then try to hack into them using automated software that runs through hundreds of thousands of passwords trying to guess the password. If they successfully guess a password, they start sending spam from that email address.
Ask your ISP to send you one of the spam emails that you are supposedly sending. There is a good chance that it DID come from your email address, but from an IP address starting with 200. If that is so, *immediately* change your email passwords. Also make sure that you do not have an automatic reply set up in your email. One of the things these spammers are doing is setting up an auto reply so that anyone who emails you is automatically sent a repy that contains a spam link.
