Replae SSH reverse tunnells and what to google

Hey all. I have Tailscale running on a couple of my machines and works well. Gets through firewalls as expected and my data gathering RPI at my sones place talks back to my home using it.

However in preperation of changing internet providers and knowing my new one only has private IP’s I went in search of a solution so I can still host my mail servers at home. (used to run them on VPS’s but too expensive these days)

So currently I use a RPI and Autossh to set up remote tunnels back into my system. It works and I like the fact I can tell it (as an example) to listed on port 25 on the cheap and basic VPS out in the world and redicrect the traffic to a machine and port on my local network

The Autossh is somewhat unreliable so I started to look at what I can do with Tailscale. My question is what do I Google? Is it NATing or is it a built in function of Tailscale I have missed?

In my mind I think it should be fairly simple but I cannot find an example

So what I am trying to do is expose port 25 on my vps and it has say a public IP address of
I have tailscale installed in that machine and basically I want to shove the incoming traffic from port 25 into the tailscale interface, have it pop up in my mail server (it has tailscale installed).

To me thats NAt or MAsqerading?

Can anyone point me in the right direction? It seems at least in my mind a fairly simple thing if I knew what to search for but yes thats in my mind :slight_smile: