Interesting, I thought changing emails was possible. I guess that you might need to private message a moderator so they can change it for you. Click on the moderator's name that I have tagged below, and on the right hand side of the page, click "send this user a private message". Cheers! 
Go to "Edit Profile" or "My Profile" in your self serve account online. You'll see a text field to change your email. By the way, welcome to Public Mobile!
