He is Courier Yu at Nanchang. Enter Nanchang from last village in Hangzhou and then go left towards SvS fortress he is outside there.
He is not there. Guess he is supposed to be there, but he ain't. Anyone done the quest can pinpoint his location ? Would be much appreciated.
In case anyone needs this answer, he is the only mob in front of the gateway into the fortress that doesn't look like a Coin Faction mob.
Thank you very much for the information ElfSlayer9, i found it . But this mob do he job patrol if not show, just wait 3 mnt in there .