In this post i will capture the installation of opendmarc and how its configure alongside Opendkim.

Install opendmarc

Configure systemd service file

The specific changes here are lines #9 EnvironmentFile #13 -p $SOCKET

Defaults File

Opendmarc Config file

Modify Postfix milters
If you are running both opendkim and opendmarc your milters will look like this:

Restart the service


Now go┬ámodify your DNS, adding a TXT record ‘_dmarc‘with the value ‘v=DMARC1; p=none;

When you have validated dmarc is working properly you can change p=none to p=reject

How can you validate it?

There are a number of tools online to help you with this, also you open up a mail in google and click ‘show original’.



Other resources