It would probably be mail.x[.]com

Is the implication here that its annoying to expect pet owners to be responsible for waste they leave behind?

Can you provide an example? I’m a little confused by what you mean.

Once the port is open, you should be able to access it via the tailscale IP just as you would locally on your network

Happy to help!

Side note, if you want to make publicly available services, you could use cloudflare tunnels. They work in a similar way – letting your services be accessible over the Internet without needing to open ports. Some other people in the comments have mentioned that Tailscale funnel can also work for this, but i haven’t used it so I can’t really advise on that front

To my understanding, yes! I touched on it in the post but since tailscale is a VPN that doesn’t require open ports to access other devices in the tailnet, you don’t need to worry about CGNAT