Published in 2015, DMARC is a newer standard for helping fight spam, but what is it and what does it do?
DMARC is an extension to the existing SPF and DKIM standards that allows you to control the rejection settings for messages that do not pass SPF and DKIM sent using your domain name.
The feature allows you to receive reports of rejected emails and even specify the level of security you'd like used when reviewing emails from your domain for rejection.
This tool helps identify and stop external malicious actors from using your domain in phishing scams and other types of spam.
Here are some external resources with more detail on the implementation, history, and use of DMARC