This program can operate in any of three user-selectable modes. Sponsored mode allows you to use all features of Eudora at no charge, but displays advertisements. Paid mode allows you to use all features of Eudora e-mail client without the advertisements once a payment has been made. Light mode includes a sponsor image or logo, but no rotating advertising; however, you only get access to Eudora's basic features. You can switch between the Light mode and the Sponsored mode at any time.