Zimbra Setups

 adduser rhouser
 passwd rhouser
 
 yum update -y ; reboot
 yum -y install which openssh openssh-server openssh-clients openssl-libs nano rsync unzip net-tools NetworkManager-tui sysstat perl-core libaio nmap-ncat libstdc++.so.6 wget tar bind-utils -y 
 yum install psmisc 
 #Install and configure firewall-cmd
 hostnamectl set-hostname "mail.rhomicom.com"
 exec bash
# nano /etc/hosts
# 192.168.0.108 mail.rhomicom.com mail

echo 'mail.rhomicom.com' > /etc/hostname
echo '127.0.0.1 mail.rhomicom.com mail' >> /etc/hosts
hostname mail.rhomicom.com
hostname --fqdn

# Do all DNS settings and MX records on Domain Registrar's DNS
dig -t A mail.rhomicom.com
dig -t MX rhomicom.com

#Install Let'sencrypt CentOS7
yum install epel-release
yum install certbot

wget https://files.zimbra.com/downloads/8.8.10_GA/zcs-8.8.10_GA_3039.RHEL7_64.20180928094617.tgz --no-check-certificate
tar zxpvf zcs-8.8.10_GA_3039.RHEL7_64.20180928094617.tgz
cd zcs-8.8.10_GA_3039.RHEL7_64.20180928094617

./install.sh
#Answer Y to all options
# Answer Yes to Create Domain 
# enter domain rhomicom.com
# enter MX mail.rhomicom.com
# Unconfigured Modules, Choose 7
# Choose 4 to set admin password
# choose r to go back
# choose a to apply all settings
# Wait for system to complete configuration and login
su - zimbra -c "zmcontrol start"
su - zimbra -c "zmcontrol stop"
su - zimbra -c "zmcontrol status"
su - zimbra -c "zmcontrol restart"

Uninstall

 cd /root/zimbra/zcs-8.8.10_GA_3039.RHEL7_64.20180928094617
 zcs-8.8.10_GA_3039.RHEL7_64.20180928094617]# ./install.sh -u

Move from Old to New Server

 # On Old Server
 tar -czvf zimbkp29Aug2021-17-39.tar.gz /opt/zimbra/
 # On New Server
 # Install Same version of ZCS
 rsync -avH [email protected]:/home/rhouser/*.t*z --progress --human-readable /home/rhouser
 tar -xzvf zimbkp29Aug2021-17-39.tar.gz
 mv /opt/zimbra /home
 mv opt/zimbra /opt
 /opt/zimbra/libexec/zmfixperms -e -v  # as root
 postfix check
 #temporarily switch to self-signed cert to avoid some SSL/TLS errors
 /opt/zimbra/bin/zmcertmgr createcrt -new -days 3650
 /opt/zimbra/bin/zmcertmgr deploycrt self
 # Alternatively you may disable TLS Connections temporarily
 su - zimbra 
 zmlocalconfig -e ssl_allow_untrusted_certs=true 
 zmlocalconfig -e ldap_starttls_supported=0
 zmlocalconfig -e ldap_starttls_required=false
 zmlocalconfig -e ldap_common_require_tls=0
 zmcontrol restart
 #Validate LDAP Configuration
  su - zimbra
  zmcontrol stop
  zmlocalconfig -s ldap_root_password
  /opt/zimbra/common/sbin/slappasswd -s Y0uRP4S5w0Rd
  #sample output - {SSHA}SXzTa82PbLST97854mZOp746PBLA2378
  cd /opt/zimbra/data/ldap/config/cn=config
  vi olcDatabase={0}config.ldif
  #CHange olcRootPW:: e1NTSEE112123gblVeVJ2UjU3UE1512312366jjkj128080as2bDQ5eVgxNXhWSlFPUWhTQmxhQ1d4L1RaNWdsdVRsWWJyRXJDcTA4V0Y0YVRYOE5ma23451wR3A1QytBZUZocEZ1
  # to  olcRootPw: {SSHA}SXzTa82PbLST97854mZOp746PBLA2378
  zmcontrol start
  # or reboot PC
  # and re-run zcs install
  ./install.sh
# Enable TLS Connections after install if they were disabled
su - zimbra 
zmlocalconfig -e ssl_allow_untrusted_certs=true 
zmlocalconfig -e ldap_starttls_supported=1
zmlocalconfig -e ldap_starttls_required=true
zmlocalconfig -e ldap_common_require_tls=1
zmcontrol restart

Install Letsencrypt Cert Zimbra

sudo certbot --version
sudo su - zimbra -c "zmproxyctl stop"
sudo su - zimbra -c "zmmailboxdctl stop"
export EMAIL="[email protected]"
certbot certonly --standalone   -d mail.rhomicom.com   --preferred-challenges http   --agree-tos   -n   -m $EMAIL   --keep-until-expiring
ls -lh /etc/letsencrypt/live/mail.rhomicom.com/

sudo mkdir /opt/zimbra/ssl/letsencrypt  #NOT NEEDED IN RENEWAL

CERTPATH=/etc/letsencrypt/live/mail.rhomicom.com
sudo \cp -rf $CERTPATH/* /opt/zimbra/ssl/letsencrypt/
ls /opt/zimbra/ssl/letsencrypt/
cat $CERTPATH/chain.pem | sudo tee /opt/zimbra/ssl/letsencrypt/zimbra_chain.pem
cat /opt/zimbra/ssl/letsencrypt/zimbra_chain.pem

#ADD THE LETSENCRYPT CERT
sudo tee -a /opt/zimbra/ssl/letsencrypt/zimbra_chain.pem<<EOF
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
EOF

cat /opt/zimbra/ssl/letsencrypt/zimbra_chain.pem
sudo chown -R zimbra:zimbra /opt/zimbra/ssl/letsencrypt/
ls -lha /opt/zimbra/ssl/letsencrypt/
sudo chown -R zimbra:zimbra /opt/zimbra/ssl/letsencrypt/
sudo chown -R zimbra:zimbra /etc/letsencrypt/
cd /opt/zimbra/ssl/letsencrypt
ls -halt
ln -sf /etc/letsencrypt/live/mail.rhomicom.com/cert.pem cert.pem
ln -sf /etc/letsencrypt/live/mail.rhomicom.com/chain.pem chain.pem
ln -sf /etc/letsencrypt/live/mail.rhomicom.com/fullchain.pem fullchain.pem
ln -sf /etc/letsencrypt/live/mail.rhomicom.com/privkey.pem privkey.pem
ls -halt
cat cert.pem
sudo chown -R zimbra:zimbra /opt/zimbra/ssl/letsencrypt/
sudo su - zimbra -c '/opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/letsencrypt/privkey.pem /opt/zimbra/ssl/letsencrypt/cert.pem /opt/zimbra/ssl/letsencrypt/zimbra_chain.pem'
sudo cp -a /opt/zimbra/ssl/zimbra /opt/zimbra/ssl/zimbra.$(date "+%Y%.m%.d-%H.%M")
sudo cp /opt/zimbra/ssl/letsencrypt/privkey.pem /opt/zimbra/ssl/zimbra/commercial/commercial.key
sudo chown zimbra:zimbra /opt/zimbra/ssl/zimbra/commercial/commercial.key
sudo su - zimbra -c '/opt/zimbra/bin/zmcertmgr deploycrt comm /opt/zimbra/ssl/letsencrypt/cert.pem /opt/zimbra/ssl/letsencrypt/zimbra_chain.pem'
sudo su - zimbra -c "zmcontrol restart"

SSH Errors on Zimbra Monitor Message Queue

#Regenerating Keys
#To regenerate the ssh keys, on all hosts (as the zimbra user):
 zmsshkeygen
#To deploy the keys, on all hosts (as the zimbra user):
 zmupdateauthkeys
#Verifying sshd configuration
#The authentication method assumes that sshd on the mta is running on port 22, and that RSA Authentication is enabled. You can test the ssh command with:
 ssh -i .ssh/zimbra_identity -o strictHostKeyChecking=no [email protected]
#You should NOT be prompted for a password; if you are, recreate the ssh keys and retry the test.
#If you're not running sshd on port 22, modify the zimbraRemoteManagementPort attribute on the server:
zmprov ms MAIL.DOMAIN.COM zimbraRemoteManagementPort 2222
#Verify in /etc/sshd_config (or /etc/ssh/sshd_config) that the zimbra user is an allow user
#AllowUsers admin zimbra

Other Zimbra Know-hows

 #Redirect http to https
 su - zimbra
 zmprov ms `zmhostname` zimbraReverseProxyMailMode redirect
 zmproxyctl restart
 su - zimbra -c "postqueue -p"

Zimbra Network Settings

  systemctl enable --now named
  vi /etc/sysconfig/network-scripts/ifcfg-eth0
  yum install bind bind-utils -y
  ip a show eth0
  nano /etc/resolv.conf
  chattr +i /etc/resolv.conf ## reverse this using -> chattr -i /etc/resolv.conf
  sudo systemctl restart NetworkManager.service
  /etc/init.d/network restart
  firewall-cmd --add-service=dns --permanent
  firewall-cmd --reload


  sudo vim /etc/NetworkManager/NetworkManager.conf
  # [main]
  dnz=none
  nmcli connection modify "System eth0" ipv4.dns 127.0.0.1
  nmcli connection down "System eth0"; nmcli connection up "System eth0"
  # On Debian $ vi /etc/dhcp/dhclient-enter-hooks.d/nodnsupdate
  # On CentOS $ vi /etc/dhclient-enter-hooks

  Append following code:

  #!/bin/sh
  make_resolv_conf(){
	:
  }
  Save and close the file. Set permissions using the chmod command:
  # On Debian $ chmod +x /etc/dhcp/dhclient-enter-hooks.d/nodnsupdate
  # On CentOS $ chmod +x /etc/dhclient-enter-hooks

Sample Named.conf

options {
        listen-on port 53 { 127.0.0.1; any;172.26.1.3;};
        listen-on-v6 port 53 { ::1; };
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        recursing-file  "/var/named/data/named.recursing";
        secroots-file   "/var/named/data/named.secroots";
        allow-query     { localhost; any; 127.0.0.1; 172.26.1.3;};

        forwarders {
                8.8.8.8;
                8.8.4.4;
                172.26.15.6;
        };

        /*
         - If you are building an AUTHORITATIVE DNS server, do NOT enable recursion.
         - If you are building a RECURSIVE (caching) DNS server, you need to enable
           recursion.
         - If your recursive DNS server has a public IP address, you MUST enable access
           control to limit queries to your legitimate users. Failing to do so will
           cause your server to become part of large scale DNS amplification
           attacks. Implementing BCP38 within your network would greatly
           reduce such attack surface
        */
        recursion yes;

        dnssec-enable yes;
        dnssec-validation auto;

        /* Path to ISC DLV key */
        bindkeys-file "/etc/named.root.key";

        managed-keys-directory "/var/named/dynamic";

        pid-file "/run/named/named.pid";
        session-keyfile "/run/named/session.key";
};

logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};

zone "rhomicom.com" IN {
                type master;
                file "rhomicom.com.zone";
                allow-update { none; };
        };

zone "." IN {
        type hint;
        file "named.ca";
};

include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";