as I said BIND can be installed on any machine on your LAN.
sorry Bill for being such a dummy....please...one more thing.....i already have bind installed to another virtual machine that runs as a web server (that part works fine....)
so i do not have to install once again bind in my (other virtual ) mail serve
That's correct, you don't have to install another copy of BIND, just use the one you already have. Just one addition point, you should make sure that your resolv.conf file (on the Zimbra server) only has your LAN DNS server IP address in it and no external DNS servers.