I've been trying to setup a split zone DNS because our mail server is behind a firewall. I know this issue has been brought up a million times but I can't seem to get it working. When I change the listening port of the DNS server to (10.1.10.199) and change our clients DNS to point to (10.1.10.199), we no longer receive emails through IMAP. When you run a digg command, it shows that mail.mydomain.com resolves to (10.1.10.199). You also can't access the web interface by typing https://mail.mydomain.com you have to use (10.1.10.199). Any guidance would be greatly appreciated, here is our setup.
Server OS = Ubuntu 12.04
Zimbra Version = 8.0.7
DNS Server = dnsmasq
127.0.0.1 localhost.localdomain localhost
10.1.10.199 mail.mydomain.com mail