Urdu CBT Linux System Administration qmail 1/7

It explains how you can configure qmail SMTP server (written by Dan Bernstein), with all the bells and whistles, using steps outlined by the creator of qmailrocks.com website (now de-functional). The qmailrocks guide was somewhat in-sufficient in explaining how qmail actually works. It just spoon-feeds you the steps to do […]

Installing Nagios core on RHEL / CENTOS 5.x – RHEL / CentOS 6.x Fedora 15/16/17/18/19/20

What is Nagios An enterprise-class monitoring and alerting solution that provides organizations with extended insight of their IT infrastructure before problems affect critical business processes. Requirements We require following things for Installing Nagios: These are Just Pre-requisites. We need them to other things work … 1. Apache and PhP (php […]

Postfix Mail Delivery SMTP Troubleshooting

To avoid delay in emails, specially for gmail. Just find which MX is working by issuing below commands: # dig mx gmail.com # telnet mx-IP/name 25 upon success, just see the name of first mx tried from /var/log/maillog and add an entry in /etc/hosts file. In my case, the entry […]