Hey guys, mailcow by default ships Postfix with mynetworks_style=subnet, which means that e.g. connections from the Docker host system will be trusted and we don’t need to authenticate SMTP connections before sending emails out.
Personally, I don’t like this. In the optimal scenario, I would just set mynetworks= , so to an empty value, which would mean that all SMTP connections would require authentication. But I heard this might create problems with some Postfix-internal redirections of mails?
So I thought to set mynetworks_style=host, so that at least the Postfix container is able to send mails un-authenticated, but everyone else is not.
My questions now are: Is there a reason for Mailcow to have it mynetworks_style=subnet by default? Can I run intro trouble when I change it to mynetworks_style=host? E.g. are there some status-emails or similiar stuff that is being sent out by some of the containers, that require Postfix for not check for authentication?