---
name: "dmarc_lookup"
section: "1p"
platform: "linux"
package: "libmail-dmarc-perl"
version: "1.20240314-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/dmarc_lookup"
---

# dmarc\_lookup(1p)

look up DMARC policy for a domain

## NAME

dmarc\_lookup - look up DMARC policy for a domain

## SYNOPSIS

```
   dmarc_lookup example.com [ --verbose ]
```

## DESCRIPTION

Query the DNS for a DMARC policy for a (sub)domain. Displays any found results as the DNS record as a perl object. In the simplest case, where the domain name in the email From header matches the *Organizational Domain*, this is roughly equivalent to the following commands:

```
    dig +short _dmarc.example.com TXT
    print $_->txtdata."\n"
      for Net::DNS::Resolver->new(dnsrch=>0)->send('_dmarc.example.com','TXT')->answer;
```

When the domain name in the email From header (header\_from) is not an Organizational Domain (ex: www.example.com), an attempt is made to determine the O.D. using the Mozilla Public Suffix List. When the O.D. differs from the header\_from, a second DNS query is sent to \_dmarc.\[O.D.\].

## EXAMPLES

A DMARC record in DNS format looks like this:

v=DMARC1; p=reject; adkim=s; aspf=s; rua=mailto:dmarc@example.com; pct=100;

DMARC records are stored as TXT resource records in the DNS, at \_dmarc.example.com.

Other ways to retrieve a DMARC record for a domain are:

## SEE ALSO

Mail::DMARC::Policy

## AUTHORS

- •

  Matt Simerson \<msimerson@cpan.org\>

- •

  Davide Migliavacca \<shari@cpan.org\>

- •

  Marc Bradshaw \<marc@marcbradshaw.net\>