Had the same problem.
My solution at the moment was to disable ipv6 in unbound as I have an ipv6 network but run mailcow on a Proxmox server in a debian 12 LXC container.
Go to the following file mailcow-dockerized/data/conf/unbound/unbound.conf
Where you see do-ip6: no
Restart the entire stack - you should now only get a slight problem with fuzzy.mailcow.email
But not enough to bring down the container.
After the docker compose down and docker compose up -d all the containers should come up
Im still working on the ipv6 issue, my docker daemon.json file looks like this but I am learning
{
"log-driver": "journald",
"dns": ["192.168.1.1", "2001:8003:9939:4000::1", "fe80::f4e2:c6ff:feee:63da"],
"ip6tables": true,
"experimental" : true,
"userland-proxy": true,
"selinux-enabled": true,
"data-root": "/var/lib/docker"
}
It should work.
My issue at the moment is SSL certificates as my global DNS entries all point to internal Ip addresses for ipv4/ipv6 and guess what I can’t get the ipv6 to run properly 🙂