This article describes how you can add a user with your school's domain who does not show on your list of users but who is clearly in the CPM system of users. This can happen when a teacher attends a workshop getting a temporary eBook using their school's email. The teacher receives the temporary eBook, but the teacher's account having been created outside of their district is NOT associated with their district. Use the following tutorial to associate the teacher with your district.
NOTE: On occasion this option will not work. Email: email@example.com explaining that you cannot add a particular teacher to your school even with the 'Add an Existing User' button. Be sure you give the teacher's first, last name, and email.