!!! Overview
[{$pagename}] ([DMARC]) is an [email] [authentication] [protocol] defined in [RFC 7489]


[{$pagename}] is designed to give email domain owners the ability to protect their [DNS Domain] from unauthorized use, commonly known as email [Spoofing Attack]. The purpose and primary outcome of implementing [DMARC] is to protect a [DNS Domain] from being used in business email compromise [attacks], [phishing] [emails], email scams and other cyber threat activities.

[{$pagename}] operates by checking that the domain in the message's From: field (also called "5322.From") is "aligned" with other authenticated [DNS Domain] names. If either [SPF] or [DKIM] alignment checks pass, then the [DMARC] alignment test passes.

!! [DNS Resource Records]
[DMARC] records are published in [DNS] with a subdomain label _dmarc, for example _dmarc.example.com. Compare this to [SPF] at example.com, and [DKIM] at selector._domainkey.example.com.

The content of the TXT [DNS Resource Record] consists of name=value tags, separated by semicolons, similar to [SPF] and [DKIM]. For example:
{{{"v=DMARC1;p=none;sp=quarantine;pct=100;rua=mailto:dmarcreports@example.com;"}}}
Here, v is the version, p is the [policy], sp the subdomain [policy], pct is the percent of "bad" emails on which to apply the [policy], and rua is the [URI] to send aggregate reports to. In this [example], the entity controlling the example.com [DNS Domain] intends to monitor [SPF] and/or [DKIM] failure rates and doesn't expect emails to be sent from subdomains of example.com. Note that a subdomain can publish its own [DMARC] record; receivers must check it out before falling back to the organizational domain record.


!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]
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* [#1] - [DMARC|Wikipedia:DMARC|target='_blank'] - based on information obtained 2019-07-18 
* [#2] - [DMARC Overview|https://dmarc.org/overview/|target='_blank'] - based on information obtained 2019-07-18 
* [#2] - [Companies still don’t understand the importance of DMARC adoption|https://www.helpnetsecurity.com/2019/07/17/companies-dmarc-adoption/|target='_blank'] - based on information obtained 2019-07-18