I'm creating the Episerver application using Episerver CMS R2.
I'm new to episerver. how to get the Episerver page last updated user email address.
If I understand you correctly you want the email address of the user that last changed a page. If you have a PageData object called page you could do the following:
string email = EPiServerProfile.Get(page.ChangedBy).Email;
Per GunsarfsEPiServer CMS development team