From the Donor Detail page, press the green "Edit" button at the top-left of the page. This will allow you to edit donor information.
The form fields to the left of the page contain the contact information for the donor. Enter or change the information and press "Update Information" to save.
"Contact Email Address" at the top-right of the page indicates where donation receipts are sent. Donors can have multiple email addresses, but receipts are only sent to one location. In the "Email Addresses" section in the middle-right, admins can add or remove emails associated with this donors. Be careful - if an admin adds an email to a donor's account, then all donations made with this email will be associated with this donor. If the donor has an account, they can sign in with any valid email.
If a user has been unable to verify their email, an admin can manually re-send a verification email from this page.