DMARC (Domain-based Message Authentication, Reporting and Conformance) is an email authentication standard that builds on SPF and DKIM. DMARC enables domain owners to specify how unauthenticated messages should be handled (none, quarantine, reject) and receive reports on sender verification.

What is DMARC used for?

DMARC dMARC (Domain-based Message Authentication, Reporting and Conformance) is an email authentication standard that builds on SPF and DKIM. DMARC enables domain owners to specify how unauthenticated messages should be handled (none, quarantine, reject) and receive reports on sender verification. Learn more in the full article above.

DMARC (Domain-based Message Authentication, Reporting and Conformance) is an email authentication standard that builds on SPF and DKIM. DMARC enables domain owners to specify how unauthenticated messages should be handled (none, quarantine, reject) and receive reports on sender verification. Detailed explanation can be found in the article above.

DMARC — email authentication standard

DMARC Definition

DMARC (Domain-based Message Authentication, Reporting and Conformance) is an email authentication protocol that enables domain owners to protect against spoofing and phishing. DMARC uses SPF and DKIM mechanisms and adds a policy layer specifying what to do with messages that fail authentication.

How Does DMARC Work?

Email sent from your-domain.com
Recipient server checks SPF and DKIM
DMARC verification - does the From domain match SPF/DKIM?
Policy application - action according to DMARC policy
Reporting - sending reports to domain owner

DMARC Policies

p=none:

Monitoring only
No action on failures
First implementation phase

p=quarantine:

Messages to spam/quarantine
Intermediate phase
User can still see messages

p=reject:

Message rejection
Maximum protection
Goal of DMARC implementation

DMARC Record

Example DNS record:

_dmarc.example.com TXT "v=DMARC1; p=reject; rua=mailto:dmarc@example.com; pct=100"

v: Version (DMARC1)
p: Policy (none/quarantine/reject)
rua: Aggregate report address
ruf: Forensic report address
pct: Percentage of messages covered

DMARC Reports

Aggregate reports (rua):

Daily summaries
Statistics on authentication
Senders using your domain

Forensic reports (ruf):

Individual message details
For incident analysis
Privacy considerations

DMARC Implementation

Inventory: All legitimate email sources
SPF: Configuring sender list
DKIM: Signing implementation
DMARC p=none: Monitoring mode
Analysis: Report review
Tightening: Gradually to p=quarantine, then p=reject

DMARC Benefits

Phishing protection: Spoofing blocking
Reputation: Domain reputation improvement
Visibility: Insight into email traffic
Deliverability: Better inbox delivery

DMARC Statistics

Organizations without DMARC are many times more likely to be phishing targets. The vast majority of the Fortune 500 have implemented DMARC.

DMARC is an essential email security standard, protecting both the organization and its recipients from spoofing attacks.

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