3.1.2 Subscription settings: Optional, Auto, Forced, Disabled
In 2014 I participated in CALMet Online. I didn't have to check the forum all the time to follow conversations because every time somebody posted on the forum I got a notification via e-mail.
This notification has wide functionality. It allows me to go directly to the course, forum, topic or even reply to this post (blue and underlined text).
On the other hand the facilitator or administrator chose auto subscription for this forum so I had an opportunity to unsubscribe myself from this forum.