August 24

Fail2Ban vs. Firewall…. FIGHT!

——————————————————————— – OVERVIEW / THOUGHT PROCESS – ——————————————————————— For months now, I’ve been dealing with customers calling about their email services being no longer available. By the time I troubleshoot the problem, their email has come back on line which created a ‘could not duplicate’ finality to the problem. As such, I got extremely curious.

July 28

Sendmail rejected — Default CentOS Installation

——————————————————————— – OVERVIEW / THOUGHT PROCESS – ——————————————————————— After completing a brand new minimal install of CentOS 6.4, I configured the installation to be a web server using apache, mysql and sshd for remote access.  After configuring a website on the box, I attempted to send an email from the local webpage, but never received.

February 28

Fedora (Let’s Make A Server!)

——————————————————————— – OVERVIEW / THOUGHT PROCESS – ——————————————————————— The first time that I installed Fedora onto a random machine was when Fedora Core 3 had just been released. I didn’t really know much about the system, but then again, I wasn’t really interested in learning it either. My true mission at that time was to.

February 22

Postfix Troubleshooting (‘TLS not available due to local problem’)

I woke up this morning with around 38 emails sitting in my postmaster email account with basically the same script that you see right below… without the $ bolded manual commands, of course.  The only thing that I could identify at the time was the last line that said ‘TLS not available due to local problem.’.