Hello, I was wondering the same thing not so long ago, I just mailed to JM. And they gave the answer:
We received your message. Please be advised that you can still modify your email address provided that you did not verify it and that you know the secret answer. Please be guided by this steps.
1. Log-in to
http://www.joymax.com/portal/2. Click on Update Email Address( Upper right of the page.
3. And then follow the steps which is required by the system
However if the email address you are pertaining to is already email verified then we will not be able to change it at this moment. As of now there is no available option to modify verified email address. We will not know if the option will be available in the future. If it will be a available rest assured that we will make an in-game announcement about regarding the issue.