Summary
Diagnosing DMARC failures involves analyzing DMARC reports to understand why emails are not authenticating correctly. These reports contain aggregate data about email authentication results and highlight SPF/DKIM alignment issues, potential abuse, and unauthorized sending sources. Leveraging DMARC analyzer tools can simplify the interpretation of these reports, and filtering by failure type (SPF, DKIM) can pinpoint specific problems. Analysis should include validating SPF records, checking for domain spoofing, cross-referencing IP addresses with threat intelligence, and identifying common failure scenarios like forwarding issues. Forensic reports offer more granular detail, and platforms like Microsoft 365 Defender provide integrated tools for viewing and interpreting these reports. It's crucial to maintain a valid email address in your DMARC record to receive these reports.
Key findings
- Authentication Data: DMARC reports provide aggregate data on email authentication results.
- SPF/DKIM Issues: Reports pinpoint SPF and DKIM alignment problems, common causes of DMARC failures.
- Spoofing Detection: DMARC reports aid in identifying and mitigating domain spoofing attempts.
- Unauthorized Sources: Reports help differentiate between authorized and unauthorized email sending sources.
- Analyzer Tools: DMARC analyzer tools simplify the process of parsing and interpreting reports.
- Forensic Detail: Forensic reports offer granular details, including email headers and content.
Key considerations
- Report Access: Ensure you have access to and regularly monitor DMARC reports.
- SPF Validation: Validate that SPF records are correctly configured to include all legitimate sending sources.
- IP Cross-Referencing: Cross-reference IP addresses in reports with threat intelligence to identify malicious actors.
- Email Address: Maintain a valid email address in the DMARC record to receive reports.
- Forwarding Impact: Be aware that forwarding practices, especially with mailing lists, can impact DMARC authentication.
- Platform Tools: Leverage tools and features offered by platforms like Microsoft 365 Defender for DMARC analysis.
What email marketers say
8 marketer opinions
Analyzing DMARC reports is crucial for diagnosing email authentication failures. By examining these reports, email marketers can pinpoint issues like SPF/DKIM misconfigurations, identify domain spoofing attempts, and differentiate between authorized and unauthorized sending sources. Utilizing DMARC analyzer tools can simplify report interpretation, while filtering by failure type helps focus on specific authentication problems. Validating SPF records and cross-referencing IP addresses with threat intelligence databases are also recommended for comprehensive analysis.
Key opinions
- Authentication Issues: DMARC reports reveal specific authentication problems such as SPF not aligning or DKIM signatures failing.
- Spoofing Detection: DMARC reports help identify instances of domain spoofing, enabling action against malicious senders.
- Source Validation: DMARC reports differentiate between authorized and unauthorized sending sources.
- Simplified Analysis: DMARC analyzer tools simplify the process of parsing and visualizing DMARC reports.
- Targeted Troubleshooting: Filtering reports by failure type (e.g., SPF, DKIM) pinpoints specific issues.
Key considerations
- SPF Validation: Validate SPF records using DMARC reports to ensure correct configuration and inclusion of all legitimate sending sources.
- Threat Intelligence: Cross-reference IP addresses in DMARC reports with threat intelligence databases to identify malicious sources.
- Valid Email Address: Ensure a valid email address is included in your DMARC record to receive reports.
- Actionable Steps: Use DMARC report insights to take action against malicious actors and ensure legitimate mail is properly authenticated.
- Tool Utilization: Consider using DMARC analyzer tools for easier interpretation and pattern identification.
Marketer view
Email marketer from Reddit suggests using a DMARC analyzer tool to parse and visualize DMARC reports, making it easier to identify patterns and sources of authentication failures.
14 May 2022 - Reddit
Marketer view
Email marketer from SparkPost explains that DMARC reports help differentiate between authorized and unauthorized sending sources, enabling domain owners to take action against malicious actors while ensuring legitimate mail is properly authenticated.
11 Apr 2025 - SparkPost
What the experts say
4 expert opinions
Diagnosing DMARC failures relies on analyzing DMARC reports to understand why emails are being rejected. These reports contain data on authentication failures, allowing identification of SPF/DKIM misconfigurations, unauthenticated mail, or domain forging. Common failure scenarios include misconfigured SPF records, DKIM signatures not aligning with the 'From' domain, and email forwarding breaking authentication, particularly impacting mailing lists.
Key opinions
- Data Source: DMARC reports contain the data needed to diagnose DMARC failures.
- Root Cause Identification: Reports help identify if failures are due to misconfigured SPF/DKIM, unauthenticated mail, or domain forging.
- Common Scenarios: Common causes are misconfigured SPF, DKIM misalignment, and forwarding issues.
- Mailing List Impact: DMARC policies can negatively affect mailing lists when forwarding breaks authentication.
Key considerations
- Report Access: Ensure you have access to your DMARC reports.
- Authentication Checks: Verify SPF and DKIM configurations are correct and aligned with your sending domain.
- Forwarding Impact: Be aware of how email forwarding, especially in mailing lists, can affect DMARC authentication.
- Domain Forging: Actively look for evidence of domain forging and take appropriate action.
Expert view
Expert from Email Geeks explains that the data for email rejections due to DMARC failures is in DMARC reports.
24 Apr 2024 - Email Geeks
Expert view
Expert from Spam Resource explains that common DMARC failure scenarios include misconfigured SPF records, DKIM signatures not aligning with the 'From' domain, and forwarding emails that break authentication.
15 Jan 2024 - Spam Resource
What the documentation says
5 technical articles
Diagnosing DMARC failures involves using DMARC reports, which provide aggregate data on email authentication results. These reports enable domain owners and administrators to identify authentication failures, potential abuse, and sources of authentication issues. The reports are structured using an XML schema and contain details on authentication results, policy applications, and source IP addresses. Forensic DMARC reports offer deeper insights, including full email headers and message content. Microsoft 365 Defender also provides a portal to view and interpret DMARC reports for identifying authentication failures and phishing attempts.
Key findings
- Aggregate Data: DMARC reports provide aggregate data about email authentication results.
- Failure Identification: The reports allow identifying authentication failures, potential abuse, and sources of authentication issues.
- XML Structure: DMARC aggregate reports are structured using an XML schema with specific details.
- Forensic Reports: Forensic DMARC reports provide detailed insights including full email headers and content.
- Platform Integration: Microsoft 365 Defender offers a portal for viewing and interpreting DMARC reports.
Key considerations
- Report Interpretation: Understand the structure and content of DMARC reports to effectively diagnose failures.
- Data Granularity: Consider using forensic reports for more detailed analysis when necessary.
- Platform Tools: Leverage platform-specific tools like Microsoft 365 Defender for report viewing and interpretation.
- Actionable Insights: Use the information in DMARC reports to take appropriate action against identified issues.
- Proactive Monitoring: Regularly monitor DMARC reports to proactively identify and address authentication failures.
Technical article
Documentation from DMARC.org explains that DMARC reports provide aggregate data about email authentication results, allowing domain owners to identify authentication failures and potential abuse.
30 Jan 2023 - DMARC.org
Technical article
Documentation from RFC 7489 explains the XML schema used for DMARC aggregate reports, including details on authentication results, policy applied, and source IP addresses.
31 May 2022 - RFC Editor
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