[MM3-users] How can I allow members of list A to post to List B and vice versa

Hi,

I am trying to setup Mailman3 for our school. There I have several groups (teachers, parents) that have their own mailling lists. But it also should be possible that the parents can sent mails to the teachers list and vice versa. The manual management via the non-members list will be very inconvenient and the command-line options that I saw so far do not include the import of non-members (mailman syncmembers and mailman addmembers). The best option I would like to have is to enter the name of List A in the non-members of List B an vice versa. All those nonmembers should not need to be moderated. How can I manage this? I would be very glad for your ideas.

Best Mario