Do you have internal DNS set up? I have my wire guard deployed on both of my pihole servers, which have local DNS entries for my internal services, which point back to my internal Traefik container for NAT translations. I know that sounds a bit complicated, but that’s how it works for my environment.

It’s literally maintained by Fedora. Not sure why he claimed that.

I’ve been running mailcow for almost 2 years with no issues. I’m not doing anything major with it, mainly using it to send myself alerts on the environment, but it does work for external purposes if I want it to as well. Updating is easy and seamless. I did get greylisted almost immediately though, so I use SMTP2Go and it works great as a free relay for the amount of mail I generate.