Mail Address?

If my user name is Christopher and that is my sign in name for my site it appears this is what it used for the mail address internally for Dolphin?  Is there an actual address for outside the membership to be used?

Christopher@???????.com is that done or is that just not an option through Dolphin?    OR is it just used internally by   "Christopher"     ??

Throughout the installation process of Dolphin you're asked to provide a E-mail address, username and password.
the Email you used throughout this process is used as the email address.

just not an option... 

Thanks Jay............