Eudora is a robust e-mail client whose features include multiple addressbook formatting options and the ability to filter, redirect, and forward mail. Eudora includes many convenient features such as the powerful search functions, multiple e-mail accounts, integrated word processor with automatic spell checking, and much more.

Versions 5+ can operate in any of three, user-selectable modes. Sponsored mode allows you to use the full-featured Eudora e-mail client at no charge, but displays a series of static onscreen advertisements. Paid mode allows you to use the full-featured Eudora e-mail client without the advertisements once a payment has been made. Light mode is an upgrade to the current Eudora Light, yet does not have as many features as the full client available in Sponsored and Paid modes. The Light mode will include a sponsor image or logo, but no rotating advertising. You can switch between the Light mode and the Sponsored mode at any time.