- a system message,
- a message from all groups you have joined as author or learner,
- a message from the course communities, if you as author are creator of the course activation and the course community is active or which you have joined as learner,
- a message, which are sent to the client, to which you are assigned as author or learner,
- a message at the personal pin wall of the author or the learner or
- a Private message to all participants of the learning group and course activation or to other participants of the learning group and to the learning assistant of the learning group.