It was necessary to build an updated mail system for a client which would handle all incoming and outgoing email, and which could handle successfully sending out an average of one million emails per day. This was based on Postfix, since Postfix is known for reliability, robustness, security, and relative ease of administration. Building a Postfix mail system capable of handling so many emails is quite a significant aim at a time when establishing a positive reputation for independent mail servers delivering high volumes of email is quite a challenging goal.Continue reading “Building a Postfix-based mail system for incoming and outgoing email, capable of successfully sending one million emails per day”
A few years ago I wrote a quite popular post for security hardening on Ubuntu 14.04, and now here’s a new version for CentOS 7 and RHEL 7. Much of it should apply to CentOS/RHEL versions 6 and 8, with some tweaks required here and there. It should also largely work with Amazon Linux and Amazon Linux 2, although again some tweaks will be required for those.
For a long time I’ve maintained a memory aid in the form of a list of useful commands which can be used on the command line for Linux, macOS (OS X), BSD, Solaris, etc., so I thought I’d list them in a blog post in case they come in useful for others. Most of these will run on any Unix-type operating system, though I’ve usually indicated where a command is OS-specific.
I was interviewed for a careers feature in the esteemed PC Pro magazine, and my article has been printed in the latest edition:
I think they’ve done a great job of editing my original monologue into a compelling description of the excitement, challenges and rewards of administering computer systems and managing infrastructure, and I hope it helps to encourage college graduates and other potentially interested individuals into the field of system administration.
In the meantime, I’ll continue to enjoy my fifteen minutes of fame…
If you have a Dell PowerEdge server with a RAID array then you’ll probably want to be notified when disks are misbehaving, so that you can replace the disks in a timely manner. Hopefully this article will help you to achieve this.
These tools generally rely on being able to send you email alerts otherwise their usefulness can be somewhat limited, so you should make sure you have a functioning MTA installed which can successfully send email to you from the root account. Setting up an MTA is beyond the scope of this article, so hopefully you already know how to do that (or you can check out my new post on setting up a Postfix-based mail system).