Postfix

Postfix is a common software component on servers for receiving or sending email. It has a lot of configuration options available, including those to improve your Postfix security. This Postfix security and privacy guide will help with hardening your Postfix configuration.

After you are finished, your system will have improved defenses against spam, abuse, and leaking sensitive data.

Why Postfix hardening?

Every service that is connected to the internet is sooner or later to be abused by automated scripts. For example, an incorrectly Postfix might send messages to everyone, instead of just your network systems. This type of configuration is called an open relay. It will get your system ending up on multiple blacklists. If it is just a test system, then you are lucky. If your customers are depending on it, then you have something to explain.