Hello. We are going to use Mail HA Cluster. It is clear for me how to load balance using DNS for mail incoming from the world if we had for example two Proxmox Mail Gateways. But how to define a smart host for example using Postfix MTA? Let say that we have: - one MTA Postfix server(storing users mails) - two Mail Gateways listening on tcp/26 port which are accesible only for MTA How to define the smart host on the MTA, that if one of the Gateway Nodes failed the MTA will use another one? Or how to define smart host on the MTA, to use Mail Gateways Load Balancing? Best regards.