Today, I was trying to set up firewall rules to drop requests for certain ports (ports that are not used by mailcow ) on my Debian 12 Mailcow server. As I usually do, I added the iptables rules and saved them with the “iptables-persistent” package from apt. Upon rebooting my server, all of the requests that had to do with Mailcow started timing out. I could not reach the webmail interface or other services that are part of Mailcow-dockerized.
later the issue got fixed when I removed the package and rebooted again.
I am not sure what is causing the problem but I believe it has to do with the package reloading the rules it saved over the rules Mailcow already established again, which messes up things in a way.
If anyone knows a compatible way I can save my rules. please let me know
also I am quite new with Mailcow and haven’t fully read the documentation yet so I am really sorry if this was mentioned somewhere in the docs and I am re-posting this known issue.