I'm getting a strage behavior from zimbra when I look into this network structure of my client; Zimbra is behind a NAT, everything is forwarded as expected and work just fine - but strangely; Zimbra is starting to act as an Open Relay (?).
Everything that came to Zimbra, came from firewall with internal ip; Example:
188.8.131.52 <---external  firewall internal IP. ----> 192.168.0.1 ---> 192.168.0.2 [Zimbra server]
As it is FORWARDING, I dunno if has to be with the "trusted networking" configured wrong or if it is the DMZ (that they DO NOT have - everything is on the LAN network in the example: 192.168.0.0/24 - including NAT-FORWARD SERVERS.
Anybody has any tip about making my client Zimbra stop acting as a open relay?