You can check and change the information from [Your Library Record] -> [Personal Info.] in OPAC.
Log in to OPAC.
Click "Notifications to Mr./Ms. _____" in "User Inquiry."
Click [Personal info.] in "Your Library Record."
Click [Change Personal Info.] on the next screen, and make your changes. (You will be able to select the updated information, such as an e-mail address, even for a reservation, ILL copy request, and ILL borrowing request.)