Nabble offers a range of web-based apps that follow the conventions used by all similar forums. The principle behind this technology is that there will be multiple areas within the forum and as trust of the user is gained by the Administrator so the user will be granted additional access to further areas.
Note that this is a very different approach to a software managed mail list. A mail list only has a single area and once subscribed a user has full access to the list and can post anything. So, a mail list either requires access by invitation or, if anyone can subscribe, there needs to be control of individual posts. Nabble does not offer control of individual posts. Administrators planning to use Nabble as a mail list need to implement an external process for inviting users to subscribe.
As with all conventional multi-level web-based forums, access within Nabble is managed through two distinct controls, "User Groups" and "Permissions". Every user will be assigned to at least one group and each group has a particular set of permissions awarded to its members.