postfix

How to configure and secure your Postfix email server

How to configure and secure your Postfix email serverOnce you have your application server up and running, you are going to need a good email server to deliver your emails. I have been using postfix for all my servers and below is the configuration I generally use. Installation of Postfix on CentOS 6 yum install postfix Sendmail is installed by default, so it... Read More »

How to confiigure fail2ban to block Brute Force IP’s by scanning postfix logs

Recently, I was looking at my postfix logs and found more than 13,000 Auth fail attempts and I was shocked. We had recently changed our user password due to a security breach, so I thought that some apps might have still not implemented the change, However after doing a reverse dig on the IP I... Read More »

What is a DMARC record and how to add it

DMARC record is mostly used to track phishing and spam. It can also be very instrumental in abolishing it if implemented correctly.   How to add a DMARC record? You need to add SPF and DKIM before you add a DMARC record. For SPf click here and for dkim go here Adding a DMARC record... Read More »

How to configure your Mail server to send email via IPv6 address

How to configure your Mail server to send email via IPv6 address I recently decided to send mail via an IPv6 address for the Following reasons 1) We will soon need to start using IPv6 addresses as we have run out of IPv4 2) How will Anti-spam techniques like DNS black list work incase of... Read More »

Postfix tips and Troubleshooting Commands

Here’s a list of stuff I user everyday and other email admins will also be using, Let me know if I missed anything List/Print current mail queue # postqueue –p # mailq If it’s a huge que, you can pipe it with tail # mailq | tail Flush the queue # postqueue -f Schedule immediate... Read More »