The system includes a simple messaging system that enables messages to be sent to other users and user-groups. You can reply to and forward messages. When initially received, the message is flagged as pending. After it's read by the addressee it is flagged as read. When a message is finished with, you can either delete it completely or flag it as complete.
There are two types of messages, user and system. System messages are those used by scheduled processes to notify of status updates or errors. (Currently only the ESCI system generates system messages.)
Note that the messaging system is very simple. Specifically:
Global ToDo list: Because messages are not private, you can set up a global todo list. The administrator creates a user called ToDo (with a password known only to the administrator so that nobody can login as ToDo). Messages sent to ToDo can be seen by everyone, and individuals can respond to and delete these messages. Thus we have a public todo notice board. You could also create a Work List for this 'todo' function but there is the benefit of being able to easily reply to or forward the messages.
Administrators note: since Message Delete is a specific 'authority' it is possible to block the deletion of message by specific users if you want them to only be able to set complete status when a message is finished with, rather than deleting it.