Some discussion topics are sensitive in nature and group members might want to send message directly to the group manager. In my case, some of my current members in one of my courses worry that if they post their responses publicly, their ideas will be stolen (niche ides, elevator pitch, etc.). They want to know if they somehow can send message directly to me...?
PS - How does the messenger messaging work? I saw the discussion on it. I added my social media info, but I'm not seeing the messenger icon in my group (or maybe I wouldn't see my own?).