Just as you take the time on the first day of class to create a positive learning experience for your students, you should use your early online communications to create a sense of community among online students. Much of what you do online is not that different from what you would do in the classroom. Setting the right tone, making students feel comfortable and safe, explaining proper ways to exchange views so that points can be made but feelings don't get hurt or sensibilities offended are all things you do every day in your classrooms. The effective use of online tools presents the same types of challenges. Remind students to reply to posts in a timely fashion and make use of Netiquette to prevent misunderstandings.
Collaboration depends upon cooperative feedback.
There are certain rules that we ask everyone to follow so that everyone understands what is expected of them as a user of the list. We expect everyone to act like mature, intelligent adults, and to treat each other courteously. Pretend you're all in a classroom together, and that your Mother or the instructor is watching. Keep the Subject heading lines relevant.