A couple days ago a user created an issue on GitHub about acme-mailcow not resolving any domain. The issue was closed without getting any answer and advising to go here.
So, I’ve just installed mailcow following the get started guide and I could login without problems in the dashboard. I’ve also added a domain and created a new mailbox but, when logging in to SOGo, I got a “No mailbox selected” screen and couldn’t do anything. Trying to use other clients like Thunderbird didn’t work at all and failed upon login.
Checking docker logs I noticed a lot of dns errors but couldn’t find a way to solve them and running docker compose exec acme-mailcow nslookup <domain> failed with any domain. As suggested by a user in the GitHub issue, I tried changing the DNS server but I later noticed that mailcow highly discourages doing this and, although it actually worked, it led to other errors and I still can’t log in from other clients.