Many Thanks to you stoli412 for dealing with iApps team~🙂
Anyway, I found out something by myself.
I believe that email setup failure seems to be appeared on only those who transferred from MobileMe to iCloud.
Which means that the one who newly joined iCloud.com account doesn't have any problem with setting up the account in iPhoto.
I tested it with my wife's iCloud account, because she just happened to be newly joined in iCloud.com.
Simply, it works fine! but when I switch the sending account with mine then error message again(Shoot!!)
I really hope iApp team could come up with something soon.
Fingers Crossed, of course!
cheers.