You can update the email address in your Intuit Account.
Log into your Online TurboTax account, and in the left column menu scroll way down to Intuit Account.
In the Intuit Account choose tab Sign In and Security.
You can change the email used for notifications there.
After you do, it may show with a link "unverified" next to it. You can click that "unverified" link and follow the steps to verify the email address.