sudo vim zimbra-ssl.sh   

 #!/bin/bash  
   
 # SSL certificate installation in Zimbra  
 # with SSL certificate provided by Let's Encrypt (letsencrypt.org)  
 # Author: Subhash (serverkaka.com)  
   
 # Check if running as root  
 if [ "$(id -u)" != "0" ]; then  
   echo "This script must be run as root" 1>&2  
   exit 1  
 fi  
   
 read -p 'letsencrypt_email [xx@xx.xx]: ' letsencrypt_email  
 read -p 'mail_server_url [xx.xx.xx]: ' mail_server_url  
   
 # Check All variable have a value  
 if [ -z $mail_server_url ] || [ -z $letsencrypt_email ]  
 then  
    echo run script again please insert all value. do not miss any value  
 else  
   
 # Installation start  
 # Stop the jetty or nginx service at Zimbra level  
 su - zimbra -c 'zmproxyctl stop'  
 su - zimbra -c 'zmmailboxdctl stop'  
   
 # Install git and letsencrypt  
 cd /opt/  
 apt-get install git -y  
 git clone https://github.com/letsencrypt/letsencrypt  
 cd letsencrypt  
   
 # Get SSL certificate  
 ./letsencrypt-auto certonly --standalone --non-interactive --agree-tos --email $letsencrypt_email -d $mail_server_url --hsts  
 cd /etc/letsencrypt/live/$mail_server_url  
 cat <<EOF >>chain.pem  
 -----BEGIN CERTIFICATE-----  
 MIIDSjCCAjKgAwIBAgIQRK+wgNajJ7qJMDmGLvhAazANBgkqhkiG9w0BAQUFADA/  
 MSQwIgYDVQQKExtEaWdpdGFsIFNpZ25hdHVyZSBUcnVzdCBDby4xFzAVBgNVBAMT  
 DkRTVCBSb290IENBIFgzMB4XDTAwMDkzMDIxMTIxOVoXDTIxMDkzMDE0MDExNVow  
 PzEkMCIGA1UEChMbRGlnaXRhbCBTaWduYXR1cmUgVHJ1c3QgQ28uMRcwFQYDVQQD  
 Ew5EU1QgUm9vdCBDQSBYMzCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEB  
 AN+v6ZdQCINXtMxiZfaQguzH0yxrMMpb7NnDfcdAwRgUi+DoM3ZJKuM/IUmTrE4O  
 rz5Iy2Xu/NMhD2XSKtkyj4zl93ewEnu1lcCJo6m67XMuegwGMoOifooUMM0RoOEq  
 OLl5CjH9UL2AZd+3UWODyOKIYepLYYHsUmu5ouJLGiifSKOeDNoJjj4XLh7dIN9b  
 xiqKqy69cK3FCxolkHRyxXtqqzTWMIn/5WgTe1QLyNau7Fqckh49ZLOMxt+/yUFw  
 7BZy1SbsOFU5Q9D8/RhcQPGX69Wam40dutolucbY38EVAjqr2m7xPi71XAicPNaD  
 aeQQmxkqtilX4+U9m5/wAl0CAwEAAaNCMEAwDwYDVR0TAQH/BAUwAwEB/zAOBgNV  
 HQ8BAf8EBAMCAQYwHQYDVR0OBBYEFMSnsaR7LHH62+FLkHX/xBVghYkQMA0GCSqG  
 SIb3DQEBBQUAA4IBAQCjGiybFwBcqR7uKGY3Or+Dxz9LwwmglSBd49lZRNI+DT69  
 ikugdB/OEIKcdBodfpga3csTS7MgROSR6cz8faXbauX+5v3gTt23ADq1cEmv8uXr  
 AvHRAosZy5Q6XkjEGB5YGV8eAlrwDPGxrancWYaLbumR9YbK+rlmM6pZW87ipxZz  
 R8srzJmwN0jP41ZL9c8PDHIyh8bwRLtTcm1D9SZImlJnt1ir/md2cXjbDaJWFBM5  
 JDGFoqgCWjBH4d1QB7wCCZAA62RjYJsWvIjJEubSfZGL+T0yjWW06XyxV3bqxbYo  
 Ob8VZRzI9neWagqNdwvYkQsEjgfbKbYK7p2CNTUQ  
 -----END CERTIFICATE-----  
 EOF  
   
 # Verify commercial certificate  
 mkdir /opt/zimbra/ssl/letsencrypt  
 cp /etc/letsencrypt/live/$mail_server_url/* /opt/zimbra/ssl/letsencrypt/  
 chown zimbra:zimbra /opt/zimbra/ssl/letsencrypt/*  
 ls -la /opt/zimbra/ssl/letsencrypt/  
 su - zimbra -c 'cd /opt/zimbra/ssl/letsencrypt/ && /opt/zimbra/bin/zmcertmgr verifycrt comm privkey.pem cert.pem chain.pem'  
   
 # Deploy the new Let's Encrypt SSL certificate  
 cp -a /opt/zimbra/ssl/zimbra /opt/zimbra/ssl/zimbra.$(date "+%Y%m%d")  
 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  
 su - zimbra -c 'cd /opt/zimbra/ssl/letsencrypt/ && /opt/zimbra/bin/zmcertmgr deploycrt comm cert.pem chain.pem'  
   
 # Restart Zimbra  
 su - zimbra -c 'zmcontrol restart'  
   
 # setting auto https redirect  
 cd /opt && touch https-redirect.sh && chown zimbra:zimbra https-redirect.sh && chmod +x https-redirect.sh  
 cat <<EOF >>/opt/https-redirect.sh  
 zmprov ms $mail_server_url zimbraReverseProxyMailMode redirect  
 EOF  
 su - zimbra -c '/opt/https-redirect.sh'  
 rm /opt/https-redirect.sh  
 fi  

 sudo chmod +x zimbra-ssl.sh  

 sudo ./zimbra-ssl.sh