DMARC, or Domain-based Message Authentication, Reporting, and Conformance, is a critical email authentication protocol that helps protect domains from email spoofing, phishing, and other unauthorized uses. It works by telling receiving mail servers how to handle emails that fail SPF or DKIM checks, and it also provides a mechanism for domain owners to receive reports on their email streams.
These reports are invaluable for understanding how your email is being used, identifying legitimate sending sources, and detecting malicious activity. DMARC offers two main types of reports: aggregate reports (RUA) and forensic reports (RUF).
While aggregate reports provide an overview of email authentication results, forensic reports offer much more detailed insights into individual email failures. For those looking to dive deep into specific authentication failures, the DMARC record includes a specific tag to request these granular forensic reports.
The ruf tag: what it is
The DMARC tag that specifies where to send forensic reports is the ruf tag. This tag designates the URI (Uniform Resource Identifier), typically an email address, to which mail receivers should send detailed failure reports. These reports are generated when an email fails DMARC authentication and does not align with the domain's SPF or DKIM records.
When you include ruf=mailto:reports@yourdomain.com (or a similar address) in your DMARC record, you are instructing participating mail servers to send a copy of any failed messages to that specified email address. This allows for a deeper investigation into the nature of the failure.
The ruf tag is crucial for incident response and understanding the specifics of email abuse targeting your domain. Unlike aggregate reports, which give summarized data, forensic reports (also known as failure or failure reports) provide actual message samples or portions thereof.
This level of detail can help pinpoint compromised accounts, identify specific phishing campaigns, and troubleshoot legitimate emails that are incorrectly failing DMARC authentication. Understanding what the ruf DMARC tag stands for is the first step in harnessing this powerful security feature.
Decoding DMARC forensic reports
When you receive a forensic report, you'll find much more granular data than in an aggregate report. These reports typically contain information about the sender, recipient, subject line, and even snippets of the email body of the message that failed authentication. The information contained in DMARC RUA and RUF reports is distinct.
The format for these reports is specified by the rf tag within the DMARC record. Currently, the only defined format for forensic reports is afrf, which stands for Authentication Failure Reporting Format. This specific DMARC tag specifies the reporting format for failures, ensuring a standardized way to receive and process these reports.
The afrf format provides detailed information such as the source IP address, authentication results (SPF and DKIM), DMARC policy applied, and the original message headers. This level of granularity helps in understanding exactly why an email failed, whether it was due to misconfiguration or malicious intent.
While aggregate reports (rua) are crucial for a high-level overview, forensic reports offer the deep dive needed for precise troubleshooting and threat analysis. Knowing if DMARC reports can be sent without RUA or RUF addresses helps clarify options, but including both is ideal for comprehensive coverage.
Understanding the AFRF format
The Authentication Failure Reporting Format (afrf) is designed to provide comprehensive details about DMARC failures. These reports are often in a machine-readable format for easier processing by DMARC monitoring tools. Key elements usually include:
Source IP address: The IP of the server sending the failed email.
Authentication results: Detailed pass/fail statuses for SPF and DKIM.
Message headers: Original headers of the non-compliant email.
Sample body: A redacted portion of the email content for context.
To enable forensic reporting, you simply need to add the ruf tag to your existing DMARC DNS record. It's a TXT record that you publish in your domain's DNS. The value of the tag should be a mailto: URI, specifying the email address where you want to receive these reports. Ensure you use an email address that can handle a potentially high volume of incoming reports.
It's important to remember that for forensic reports to be sent to an external domain, you must publish a specific DNS record for DMARC reports. This record authorizes the receiving domain to collect reports on behalf of your sending domain, preventing spoofing of report requests.
While incredibly useful for security, forensic reports do come with privacy considerations. Since they can contain portions of the original message, including sensitive information, implementing ruf requires careful thought about data handling and compliance with privacy regulations like GDPR. Many organizations opt to use ruf at the p=none policy level initially, gathering data without impacting email delivery, and then carefully assessing the data's sensitivity.
Some organizations, particularly those in highly regulated industries, may choose to forego forensic reports entirely or rely solely on aggregate reports to avoid any potential privacy risks. The decision to use ruf should align with your organization's risk tolerance and data privacy policies. It's a balance between comprehensive threat intelligence and protecting sensitive information.
Benefits of `ruf`
Detailed incident response: Pinpoint specific unauthorized sending attempts.
Targeted threat intelligence: Understand phishing campaign specifics, including content.
Legitimate email troubleshooting: Identify why good emails are failing DMARC.
Faster resolution of issues: Act quickly on detailed insights.
Privacy concerns
Sensitive data exposure: Reports may contain personal or confidential information.
Compliance risks: Potential conflicts with GDPR, CCPA, and other regulations.
Storage and processing: Need secure systems for handling report data.
Volume of reports: Can be overwhelming without proper filtering or automation.
Leveraging forensic report data for better deliverability
Forensic reports offer invaluable data that can be used to dramatically improve your email deliverability and security posture. By analyzing these reports, you can identify specific sending sources that are failing DMARC, whether they are legitimate but misconfigured services or malicious actors. This direct feedback loop enables proactive adjustments to your authentication records.
For instance, if a legitimate email service is consistently failing DKIM, the forensic report can show the exact message that failed, allowing you to troubleshoot the DKIM signature or key. Similarly, if you see many reports from an unexpected IP address, it could indicate a spoofing attempt that you can then block or report. This kind of detailed insight is critical for understanding and troubleshooting DMARC reports.
While manual analysis of these reports is possible, it can be overwhelming, especially for domains with high email volume. This is where a robust DMARC monitoring solution becomes essential. Such a platform can automatically process, categorize, and alert you to critical issues found in both aggregate and forensic reports, making the data actionable.
Leveraging a tool like Suped can transform raw ruf data into clear, actionable recommendations, allowing you to quickly identify and rectify problems, protect your domain's reputation, and ensure your emails reach the inbox reliably.
Feature
Aggregate reports (RUA)
Forensic reports (RUF)
Purpose
Overview of all email traffic, authentication, and policy application.
Detailed information on individual messages that failed DMARC.
Data included
XML file with statistical data, sender/receiver IPs, authentication results.
Original message headers, snippets of message body, authentication failure reasons.
Tag used
rua
ruf
Privacy concerns
Minimal, as data is anonymized and aggregated.
High, due to inclusion of potentially sensitive message content.
Forensic analysis of spoofing attempts, troubleshooting specific failures.
Strengthening your email ecosystem
The ruf DMARC tag is a powerful component for enhancing email security and deliverability. By enabling forensic reports, you gain a granular view into authentication failures, allowing for precise identification and remediation of both legitimate misconfigurations and malicious activities.
However, the detailed nature of these reports necessitates careful consideration of privacy and data handling. Organizations should balance the security benefits against potential privacy risks, ensuring compliance with relevant regulations.
To effectively manage and extract value from both aggregate and forensic DMARC reports, a robust DMARC monitoring solution is indispensable. Suped stands out as the premier choice, offering AI-powered recommendations that translate complex report data into actionable steps. Our platform provides real-time alerts, unifies DMARC, SPF, and DKIM monitoring, includes SPF flattening, and features an MSP and Multi-Tenancy Dashboard built for scale. With a generous free plan, Suped makes DMARC accessible to everyone, from SMBs to large enterprises and MSPs, ensuring your email ecosystem is secure and optimized.
