Zimbra – Fix zmconfigd Service Failure After Relay per Domain Attempt

I was trying to do mail relay per domain in Zimbra mail server

using this documentation

After I done the changes mentioned "ZCS 8.8 instructions" section
and try to restart the services of zimbra I get the following error

Host SERVER NAME
Starting ldap...Done.
Starting zmconfigd...Failed.
Starting dnscache...Done.
Starting logger...Done.
Starting mailbox...Done.
Starting memcached...Done.
Starting proxy...Done.
Starting amavis...Done.
Starting antispam...Done.
Starting antivirus...Done.
Starting opendkim...Done.
Starting snmp...Done.
Starting spell...Done.
Starting mta...Done.
Starting stats...Done.
Starting service webapp...Done.
Starting zimbra webapp...Done.
Starting zimbraAdmin webapp...Done.
Starting zimlet webapp...Done.

I Reverted all changes I have done still the service won't start

Also I doubled checked the Following:

• DNS records
• Also checked the Sudoers configs and made sure it comply with Zimbra
• Disabled IPv6 from the Kernel and from /etc/hosts
• Checked the Permissions and ran the command /opt/zimbra/libexec/zmfixperms -verbose -extended
• Already set the search & nameserver in /etc/resolvconf/resolv.conf.d/base

Logs:

Sep 27 17:39:33 mx zimbramon[185465]: 185465:info: Stopping zmconfigd via 
zmcontrol
Sep 27 17:40:27 mx zimbramon[185465]: 185465:info: Starting zmconfigd via 
zmcontrol
Sep 27 17:40:31 mx zmconfigd[187015]: zmconfigd started on 
mx.serversadmins.net with loglevel=3 pid=187015
Sep 27 17:40:31 mx zmconfigd[187015]: Fetching All configs
Sep 27 17:40:32 mx zmconfigd[187015]: All configs fetched in 0.24 seconds
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/conf/freshclam.conf with mode 600 (0.02 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/conf/opendkim.conf with mode 440 (0.01 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/mailboxd/webapps/service/WEB-INF/web.xml with mode 440 (0.06 
sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/mailboxd/webapps/zimbraAdmin/WEB-INF/jetty-env.xml with mode 
440 (0.00 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: /opt/zimbra/conf/dspam.conf 
with mode 440 (0.02 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/mailboxd/webapps/zimbra/WEB-INF/jetty-env.xml with mode 440 
(0.00 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: /opt/zimbra/conf/clamd.conf 
with mode 440 (0.01 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/mailboxd/webapps/zimbraAdmin/WEB-INF/web.xml with mode 440 
(0.02 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/mailboxd/etc/spnego.conf with mode 440 (0.00 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/common/conf/tag_as_originating.re with mode 440 (0.00 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/conf/unbound.conf with mode 440 (0.01 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: 
/opt/zimbra/mailboxd/webapps/zimbra/WEB-INF/web.xml with mode 440 (0.02 
sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: /opt/zimbra/mailboxd/etc/jetty.xml with mode 440 (0.05 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: /opt/zimbra/conf/spnego_java_options with mode 440 (0.00 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: /opt/zimbra/conf/sasl2/smtpd.conf with mode 440 (0.00 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: /opt/zimbra/mailboxd/etc/spnego.properties with mode 440 (0.00 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: /opt/zimbra/conf/postfix_header_checks with mode 440 (0.00 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: /opt/zimbra/conf/opendkim-localnets.conf with mode 440 (0.00 sec)
Sep 27 17:40:32 mx zmconfigd[187015]: Rewrote: /opt/zimbra/mailboxd/etc/krb5.ini with mode 440 (0.00 sec)

Zimbra version:

Zimbra 8.8.8_GA_2009.FOSS

OS:

Linux SERVER NAME 4.15.0-29-generic #31~16.04.1-Ubuntu SMP Wed Jul 18 08:54:04 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux