Understanding DMARC Reports: A Practical Guide
Types of DMARC Reports
DMARC generates two types of reports:
1. Aggregate Reports (RUA)
- Sent daily by email providers
- XML format (usually gzipped)
- Contain summarized data about all emails from your domain
- Specified via the
ruatag
2. Forensic Reports (RUF)
- Sent in real-time when authentication fails
- Contain details about individual failing messages
- Specified via the
ruftag - Many providers don't send these due to privacy concerns
Anatomy of an Aggregate Report
Aggregate reports are XML files with this structure:
Report Metadata
<report_metadata>
<org_name>google.com</org_name>
<date_range>
<begin>1708905600</begin>
<end>1708992000</end>
</date_range>
</report_metadata>
This tells you who sent the report (Google) and the time period it covers (usually 24 hours).
Published Policy
<policy_published>
<domain>example.com</domain>
<p>reject</p>
<pct>100</pct>
</policy_published>
This reflects the DMARC policy the reporter found for your domain.
Individual Records
<record>
<row>
<source_ip>209.85.220.41</source_ip>
<count>1523</count>
<policy_evaluated>
<disposition>none</disposition>
<dkim>pass</dkim>
<spf>pass</spf>
</policy_evaluated>
</row>
</record>
Each record represents a group of emails from a specific IP address.
Key Metrics to Monitor
Pass Rate
The percentage of emails that pass both SPF and DKIM alignment. Target: 95%+ before moving to enforcement.
Top Sending Sources
Identify all IP addresses sending email as your domain. Cross-reference with your known email services to spot unauthorized senders.
Disposition Breakdown
- none — Email was delivered (no enforcement)
- quarantine — Email was sent to spam
- reject — Email was blocked
SPF vs DKIM Results
Track which authentication method is failing. Common patterns:
- SPF fails, DKIM passes — Usually forwarded email (normal)
- SPF passes, DKIM fails — DKIM may not be configured for that sender
- Both fail — Likely spoofing or misconfigured sender
What to Look For
Legitimate senders failing authentication
If you see Google IPs (209.85.x.x) or Microsoft IPs (40.107.x.x) failing, your SPF or DKIM is misconfigured for those services.
Unknown high-volume senders
Large volumes from unrecognized IPs could indicate spoofing. Investigate with a reverse DNS lookup.
Geographic anomalies
If you only operate in the US but see high volumes from unexpected countries, it may indicate abuse.
Making Reports Actionable
Raw XML reports are hard to read. Tools like DMARC.WS automatically:
- Parse the XML into readable dashboards
- Identify sending sources by vendor (Google, Microsoft, SendGrid, etc.)
- Track your pass rate over time
- Alert you when authentication rates drop
- Visualize sending patterns on geographic maps
Report Frequency
| Provider | Frequency | Notes |
|---|---|---|
| Daily | Very reliable | |
| Microsoft | Daily | Sometimes delayed |
| Yahoo | Daily | Reliable |
| Apple | Daily | Newer, improving |
| Others | Varies | Some send weekly |
Best Practices
- Set up RUA from day one — There's no downside to receiving reports
- Use a dedicated reporting service — Don't send reports to your personal inbox
- Review weekly — Check for new senders and authentication failures
- Act on failures — Fix SPF/DKIM issues before they affect deliverability
- Keep historical data — Trends over time are more valuable than snapshots