When you get a new API key from Evernote, it will only work in the sandbox. The sandbox is a separate instance of the Evernote service specifically designed as a safe environment for you to develop your applications without worrying about messing up your actual Evernote account or impacting our production service.
Remember everything important
A single place for your notes, ideas, lists and reminders.
Stay organized, wherever you are
Plan, keep records, and manage projects from any device–even offline.
Provide team collaboration
Manage projects, deadlines, clients, and meetings with ease.