The Messages feature gives each course a private and secure system for communication that functions similar to email. Keep in mind that Messages cannot be sent or received outside of the users in the course.
Messages are usually accessed through the Communications area of a course. Although, as with most features, the Instructor can restrict access or change the layout of the Course Menu so that Messages are accessible directly.
To access messages, from the main course view, click either on Communication>Messages, or if you have made Messages a separate button, click on that button. You will see a screen similar to this:

Instructors can also access Messages from the Course Control Panel.
Functions
The table below details the functions available on the initial Messages page.