I am experiencing issues with one of the settings on our mailing list (dev@ml.whitebox.aero), hosted on your services. When I try to set this setting to anything else, it just reverts to "Discard":

This is very disruptive for us, as we have threads that include non-members, and their emails are silently discarded - which is problematic and very confusing to everyone. Could you fix that? We need anyone to be able to write on the mailing-list, preferrably accepting them immediately rather than going through the moderation queue, which can take time to be processed.