Yes, there is Exchange Server to host it yourself or Exchange Online which is the subscription based cloud service (Microsoft 365).

Ah, understood. It depends on your client OS, e.g. for Linux it should be possible. You just need to configure no nameservers in Netbird: https://docs.netbird.io/manage/dns#default-behavior-no-nameservers-configured

I use Netbird and Pi-Hole, but I don't understand what issues you're having. If you're connected to Netbird, you should be able to use the Netbird DNS names to reach other devices, e.g. fileserver.netbird.cloud

Depends on if the friend is paying for the service :P

https://anubis.techaro.lol/docs/admin/botstopper

Hm... Maybe then I'm confusing it with the cert renewal in Home Assistant.

I used traefik in the past, but moved to Caddy a while ago. In traefik I had to restart the service to apply the renewed certificate, which I found annoying. Caddy on the other hand just works <- Edit: might be wrong

Anyway, are you using anything by the Linux Foundation?

There are some commercial Certificate Authorities that offer free certificates. But in contrast Let's Encrypt is a non-profit.

• ZeroSSL (Austria)
• Actalis (Italy)

While Netbird is generally just one of the many alternatives to Tailscale, they also do have a Reverse Proxy feature that allows access without a Netbird client. Haven't tested it yet, seems to be in beta.

https://docs.netbird.io/manage/reverse-proxy

https://nja.la/

Thanks a lot! Highly appreciated :)

You mentioned that you can't ping the remote VM. Have you checked if the remote VMs IP is reachable? Is it in the ARP table? Check with arp -a