I’ve got an error during deploying chatmail on an fresh Debian12, or Ubuntu22.04 Installation on a VPS.
unbound error: can’t bind socket: Cannot assig>
unbound fatal error: could not open ports
I tried many things, too much to write it down here.
Maybe someone can bring on the road again.
I think I also had this problem while deploying my chatmail server (https://arcanechat.me) IIRC the reason was that the provider had IPv6 disabled, I don’t remember exactly how I solved it, I managed to make it work with IPv6 but currently I am not using IPv6 in my server because it was problematic (it seems that is why the VPS provider made me opt-in to it)
Go to your chatmail.ini file and try disabling IPv6:
# if set to "True" IPv6 is disabled
disable_ipv6 = True
also remove the IPv6 records from your DNS configuration