August 24

Fail2Ban vs. Firewall…. FIGHT!

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

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!)

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’)

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.’.