hi, I use iredmail successfully on many linux distributions, even on raspbian 9 on raspberry, the problem arises on new raspberry with new raspios-buster-armhf-lite image
I discovered that from the official repositories there are problems with the installation but I don't understand what, iredmail works and is installed but does not receive emails from others as if something was blocked, in fact only on this version of raspbian the file is not created /etc/default/iptables

in previous versions everything is created and runs smoothly, i think it is an iptables problem or whatever, who could help me?

i tried to create the same file(/etc/default/iptables) but it doesn't work.