Its not possible to setup listen interfaces for smtp proxy.
The proxy works with 0.0.0.0
Same problem with TLS. -> no way to disable tls or smtp for specific if/add-ip
Disabling TLS can be done per remote hosts or nets. If you want to limit SMTP access to certain hosts, you can use the new "Upstream/Relay-Hosts only" feature.
The Problem starts with addional WAN-IP. Each of them listens on smtp-proxy. Of course, i can put all addional Wan-IPs into SMTP-Proxy Skiplist.
In my eyes listeing on 0.0.0.0 is a general problem, regardless of proxyservice:
3 moth ago, one of my customer make a pen-test basend on my documention.
Result: All AstaroProxyservices was listen on additonial IPs and this was NOT documented by me.