The reason I keep saying the same thing over and over is because your DNS is screwed (and you ahven't corrected it), you need to fix itthen uninstall Zimbra then re-install zimbar when you've got the DNS sorted. This error:
indicates what your problem is. Have you looked at the links I gave you? Have you set-up your DNS in the manner shown in those articles? The forum is littered with details of why LDAP won't start when the DNS set-up is wrong.
DNS ERROR resolving MX for webmail.cntit.com
It is suggested that the domain name have an MX record configured in DNS
checking isEnabled zimbra-mta
zimbra-mta is enabled
MX: webmail.cntit.com (127.0.0.1)