In the Messages tool, when composing a message the user may select generic recipients in the "To" field such as "All Participants", "X Role", "X Group", etc. Students may abuse these options, potentially "spamming" the lists. Another use case would be a very large (500 students) only-online course where the instructor wants to use Messages as an instructor-student tool to help students. Being able to limit the potential audience is important for courses like this where the instructor wants to create a very controlled environment.
This feature introduces the following permissions that may be set to control which roles have access to the "Groups", "Roles", and "All Participants" options when composing a message.
These permissions will require backfill for existing sites.
msg.permissions.allowToField.groups = Allow Groups in the "To" field
msg.permissions.allowToField.allParticipants = Allow the 'All Participants' option in the "To" field
msg.permissions.allowToField.roles = Allow Roles in the "To" field