Email Protection

Hi guys.

I just got a new Mail gateway (Proxmox) for my internal Mail server.
As for now, it seems to work well, but whenever I stop the SMTP proxy, it stops working.
Some steps I already made:

  1. remove all from "Routing".
  2. Define Nat - to and from the "Proxmox".
  3. made rule in the Firewall which allow SMTP to "Proxmox".

What do I miss here?

Regards,
Goldy