To receive an email notification of any new user submissions to a forum:
click on the title of a forum, a list of threads appears; next
click the subscribe link at the very top of the thread list page.
You need to be logged in for the subscribe link to appear
You need to subscribe to each forum if you want all of them - there is no 'master subscribe'.
When you post to a forum without logging in (as a 'visitor'), there will be a lag of a few minutes before your post will display (you need to refresh your browser for the change to display). There is no such delay if you register and log in to the system.