I just managed to setup a mail-in-a-box server which works well and now I’m playing with aliases. Basically, I want to send messages to a mail list but only some mail users should be allowed to do this. All mail users are in the same domain.
I have created an alias like name@domain, a list of mails to forward to and some permitted senders, but it seems that any mail users outside of permitted senders still can send mails to the group as well.
Any ideas about how can I do this?