Summary
Receiving multiple DMARC reports for the same domain at the same time can seem unusual, particularly if you're expecting a single consolidated report. However, this phenomenon is often normal and points to specific configurations or behaviors in the email ecosystem. Understanding why this happens is crucial for accurate DMARC monitoring and maintaining good email deliverability.
Key findings
- Different receiving domains: Each mailbox provider (like Yahoo, Gmail, Outlook, etc.) sends its own DMARC aggregate report. If your emails are received by multiple domains, you will get a separate report from each of them.
- Unique report IDs: Even if reports arrive at the same time from the same organization (e.g., multiple Yahoo internal systems), they should have distinct report IDs, as mandated by DMARC specifications to prevent duplication.
- Policy evaluation details: DMARC reports provide details on SPF and DKIM authentication results, as well as how the DMARC policy (p=none, p=quarantine, p=reject) was applied. A 'fail' in the policy section means the SPF or DKIM domain did not align with the header-from domain.
- Submitting domains: The subject line or filename of the DMARC report email usually indicates the submitting domain (the mailbox provider sending the report), helping you identify the source of each report.
Key considerations
- Verify report IDs and message IDs: Always check if the report_id within the XML or the email's Message-ID header are identical across the multiple reports. If they are different, the reports are unique, even if they arrive simultaneously.
- Understand reporting frequency: Different ISPs send DMARC reports at varying frequencies (daily, hourly, etc.). This can lead to a batch of reports arriving concurrently, especially at the start of a new reporting cycle.
- Review DMARC XML structure: Familiarize yourself with the DMARC XML schema to correctly interpret the different sections, particularly the policy_evaluated section which indicates how DMARC was applied, distinct from raw SPF or DKIM results. You can find more details in the DMARC aggregate reporting specification.
- Identify receiving domains: The org_name and the email in the report_metadata section of the XML specify which organization generated the report. Learn more about which ISPs deliver DMARC reports.
- Centralized reporting: To effectively manage numerous reports, consider using a DMARC monitoring platform that aggregates and visualizes this data. This can help make sense of the volume and provide actionable insights into your DMARC report volume.
What email marketers say
Email marketers often encounter high volumes of DMARC reports, leading to questions about their normal frequency and content. Their discussions frequently revolve around distinguishing legitimate reports from duplicates, understanding the various senders of these reports, and interpreting the authentication results to improve email deliverability. A common point of confusion is differentiating between their sending domain and the various receiving domains that generate these reports.
Key opinions
- Volume is normal: Many marketers note that receiving numerous reports, even at the same time, is typical because different receiving domains (ISPs) send their own unique reports based on the email traffic they process.
- Check report identifiers: A key piece of advice is to check the Message-ID of the email and the report_id within the XML file. If these are unique, the reports are not true duplicates but rather distinct reports.
- Understanding SPF vs. DMARC policy: There's often confusion between an SPF 'fail' and a DMARC policy 'fail.' Marketers emphasize that DMARC passes if either SPF or DKIM aligns with the header_from , not just if SPF passes.
- Identifying the reporter: It is important to check the org_name in the DMARC XML to confirm which entity (e.g., Yahoo, Gmail) is sending the report.
Key considerations
- Aggregate multiple reports: Manual parsing of many DMARC reports is impractical. Marketers should use tools or scripts to aggregate and interpret the data efficiently. This helps to accurately interpret DMARC reports.
- Focus on policy alignment: Rather than getting stuck on individual SPF or DKIM failures, prioritize understanding the DMARC policy evaluation, which determines the email's fate. For common issues, see how to fix common DMARC issues.
- Distinguish email sources: When SPF fails but DKIM passes, it often indicates a third-party sender where SPF might not align due to forwarding or different envelope-from domains, which is normal as long as DKIM aligns. More context on how different providers handle DMARC reporting can be found in this article on DMARC reporting.
Marketer view
Marketer from Email Geeks asks about receiving the same DMARC report fifteen times at the exact same time, questioning if this behavior is normal. They are specifically asking about reports from a single domain.
Marketer view
Marketer from Email Geeks initially asks for more details regarding the issue. They suggest checking if the Message-ID of the email or the report ID of the XML are identical across all fifteen messages.They also point out that recipients typically send one report per domain, so having the same RUA for multiple domains could lead to such a scenario.
What the experts say
Experts in email deliverability emphasize that the perceived duplication of DMARC reports is almost always a misunderstanding of how the reporting mechanism works. They consistently point out that reports are generated by receiving domains based on their own processing of mail, leading to a unique report from each distinct reporter. The key lies in understanding the difference between the sender's domain and the many receiving domains.
Key opinions
- Per receiving domain: Experts stress that DMARC reports are sent per receiving domain, meaning if your mail reaches 15 different domains (or internal systems within one large domain), you'll get 15 different reports.
- Report ID and Message-ID are key: The uniqueness of the Message-ID in the email header and the report_id in the XML confirms that these are distinct reports, even if they cover the same sending domain.
- SPF policy evaluation: Experts clarify that a 'fail' in the SPF section of the DMARC policy evaluation doesn't mean SPF itself failed, but rather that the SPF domain didn't align with the header_from domain for DMARC purposes, which is a common scenario with third-party senders.
- Identifying the reporting entity: They advise checking the email subject and the org_name in the XML to determine which specific email service provider sent each report.
Key considerations
- Understand DMARC alignment: It's essential to grasp that DMARC passes if either SPF or DKIM aligns with your header_from domain. A single failing authentication method does not necessarily mean DMARC failed overall. For more details, see our guide on DMARC, SPF, and DKIM.
- Automated processing: Manually sifting through numerous DMARC reports is inefficient. Experts recommend using automated DMARC analyzers to parse and visualize these reports, simplifying the monitoring process. This helps in understanding why your DMARC success rate is dropping.
- Consider email forwarding: Email forwarding can sometimes break SPF alignment, leading to SPF 'fail' results in DMARC reports even for legitimate emails. However, if DKIM remains intact and aligns, DMARC can still pass. This is a common challenge and is discussed in depth in this article on external domain verification for DMARC.
Expert view
Expert from Email Geeks explains that DMARC reports are sent on a per-receiving domain basis. This means if mail from your domain is processed by multiple different receiving systems, each system will generate and send its own distinct report.They emphasize the need to check if all reports share the same receiving domain and report ID to determine if they are truly identical.
Expert view
Expert from Email Geeks offers a crucial side note: the SPF 'fail' reported in the DMARC XML refers to the SPF in the policy section, not necessarily a raw SPF authentication failure. They clarify that DMARC passes if either DKIM or SPF aligns with the header_from , and in the example given, DKIM appears to be passing.
What the documentation says
Official DMARC documentation and related RFCs (Request for Comments) clarify the structure and expected behavior of DMARC aggregate reports. These specifications are designed to ensure consistency and prevent ambiguity in reporting, even when multiple reports are generated for a single domain. They define what constitutes a unique report and how receiving entities should generate them.
Key findings
- Unique report identifiers: The DMARC aggregate reporting specification mandates that each report must contain a unique report_id to help receivers identify duplicate reports if they occur.
- Report generation by receiving domains: DMARC reports are generated by the Mailbox Providers (receiving domains) that process your email traffic. Each distinct provider or even internal system within a provider will send its own report.
- Aggregate report content: Reports include metadata about the reporting organization, the date range, and records detailing the source IP, mail count, and DMARC policy evaluation results (DKIM and SPF authentication results and alignment checks).
- XML format: DMARC aggregate reports are typically delivered as XML files, often compressed within a ZIP archive, requiring parsing for human readability.
Key considerations
- RFC compliance: The behavior of DMARC reporting, including the generation of unique report IDs, is defined within the official DMARC RFCs (e.g., draft-ietf-dmarc-aggregate-reporting-15), ensuring a standardized approach across different mailbox providers.
- Understanding disposition : The disposition field within the policy_evaluated section indicates the action taken based on your DMARC policy (e.g., 'none', 'quarantine', 'reject'). It's separate from individual SPF/DKIM pass/fail results. Our list of DMARC tags explains this further.
- Data aggregation: The purpose of aggregate reports is to provide a comprehensive overview of email authentication results over a period, allowing senders to identify trends and unauthorized sending sources. While individual reports might seem repetitive, their collective data is valuable. Refer to understanding and troubleshooting DMARC reports.
Technical article
Documentation from IETF Datatracker outlines that DMARC aggregate reports must contain a unique identifier. This report_id is crucial for receiving parties to distinguish between distinct reports and avoid processing accidental duplicates.
Technical article
Documentation from DuoCircle explains that a DMARC aggregate report provides daily insights into email streams, detailing who is sending emails using your domain, even if they aren't authorized. The volume of reports directly correlates with the amount of traffic your domain generates across various mail exchangers.
Related resources
7 resources
Related pages
How many DMARC report emails should I expect to receive daily and how should I manage them?
Which ISPs deliver DMARC reports and what configuration is needed?
What DNS record is required for DMARC reports to an external domain?
List of DMARC tags and their meanings
A simple guide to DMARC, SPF, and DKIM
Understanding and troubleshooting DMARC reports from Google and Yahoo
How to fix common DMARC issues in Microsoft 365 and Google Workspace
How to interpret DMARC reports for unrecognized email sending sources and low volume DMARC failures?
Why is my DMARC success rate dropping?
The benefits of implementing DMARC
