What are messages?
Unlike some online course management programs, Moodle does not have a built-in internal email system. It does, however, have a simple system for sending messages between course participants.
Moodle messages are messages sent from one individual to another via the Moodle messaging system. In addition, these messages may be forwarded to an individual's school email account under certain circumstances. No attachments, images, or special formatting are allowed in a message.