OTRS 5 on CentOS 6.9

Access http://yourserver/otrs/installation.pl from your browser to start installation process. After installation process, run this command in shell to run OTRS Daemon.

Comodo EssentialSSL on Zimbra 8.6

Submit commercial.csr to Comodo, after approval process you’ll get email from Comodo with your EssentialSSL Certificate in zip file. After download, upload zip file to your mailserver and extract it.