If you can login to your account you can add or change your email address by clicking on edit account, as shown here:

If you cannot see your account details click on the My Account link at the top right of the screen, as shown here:

Once your email address is added you will receive a courtesy reminder that your books are due back three days before they are due; if you request an item you will receive an email when it is ready for collection, and you will receive overdue notices by email.

If you cannot login to your account, for example if you do not have a valid PIN, then you'll will need to ask a staff member to add your email address for you.