I know you said in previous posts that you could ping the Zimbra server from the 192.168.2.x network, but unless I missed something you previously only indicated that you were trying to access the web client via the IP address of the server. All I'm saying is that if you do not have DNS properly working in the 192.168.2.x network to the point where you can ping / access the Zimbra server via the FQDN of the server then that is a problem. Not saying it is *the* problem causing you not to be able to connect, but I would certainly resolve this issue first.
Mm as I told you in a past message, we can ping from 192.168.2.x to the Zimbra server, but cannot access Zimbra web client from that network, not typing server's name, not typing IPs server.
As I've said in previous responses, as far as I know you should not have to make any configuration changes in order to allow other networks access to the web client; certainly not by manually editing the httpd.conf file or anything like that. The only spot that I am aware of where you may need to give other networks access is in the Admin Console under Server Settings --> MTA --> MTA Trusted Networks. I do not believe this has any affect on the web client though.
I think the first step is to look for networks restriction, maybe in the httpd configuration ??
You don't have apache or some other web server software, besides what is installed by Zimbra, running on your server do you? It seems like this would cause issues even on the local LAN, but I'm running out of ideas as to where the problem might lie.