Can DMARC reports be sent without RUA or RUF addresses?

Key findings

• Unusual occurrence: Reports should not be sent if rua or ruf tags are absent from the DMARC record. The presence of just v=DMARC1; p=none; does not trigger report generation to an unspecified address.
• Phishing risk: An unsolicited DMARC report, especially one received without configured reporting addresses, could be a phishing attempt. Always verify the authenticity of such emails.
• No implicit reporting: Major email providers (like Gmail, Yahoo, AOL) adhere strictly to DMARC specifications. They will not send aggregate or forensic reports to a domain administrator's default contact email or any address not explicitly listed in the DMARC record.
• Record forwarding: If the DMARC record was previously configured with rua or ruf addresses and subsequently changed, some residual reports might theoretically be sent if the record updates have not fully propagated or if a receiving system cached an older record. However, this is unlikely for new reports.

Key considerations

• Validate report authenticity: If you receive an unexpected DMARC report, inspect its full headers and content meticulously. Look for discrepancies, suspicious links, or unusual sender addresses. It's crucial to understand how to troubleshoot DMARC failures and suspicious activity.
• DMARC record configuration: To receive legitimate DMARC reports, you must explicitly include rua (for aggregate reports) and/or ruf (for forensic reports) tags with valid mailto: email addresses in your DMARC TXT record. This is a fundamental aspect of DMARC tag definition.
• Monitor DNS changes: Ensure that your DNS records are correctly propagated after any DMARC record changes. Incorrect or delayed propagation could lead to unexpected behavior.
• Leverage DMARC monitoring: For accurate DMARC reporting and insights, utilize a DMARC monitoring service. These platforms help analyze aggregate reports, identify legitimate sending sources, and detect unauthorized email activity. You can learn more about a guide to RUA and RUF DMARC reports to set up proper reporting.

Ultimately, receiving DMARC reports without specifying rua or ruf addresses is highly improbable under normal circumstances and should be treated with skepticism and careful examination.

Key opinions

• Confusion and skepticism: Marketers are generally surprised and skeptical about reports being sent without explicit RUA/RUF configuration, as it contradicts established DMARC practices.
• Source attribution: There's a strong desire to understand the origin of such unexpected reports, particularly if they appear to come from major email providers.
• Legitimacy verification: Despite initial disbelief, marketers would typically perform a basic check to see if the report looks like a legitimate report before dismissing it entirely.
• Importance of explicit configuration: The consensus among marketers is that explicit configuration of RUA/RUF is essential for predictable and reliable DMARC reporting.

Key considerations

• Preventing deliverability issues: Marketers must understand that DMARC reports are crucial for identifying and resolving email deliverability problems, especially when moving to stricter policies like p=quarantine or p=reject. Proper reporting is key to avoiding email blocking.
• Monitoring unauthorized use: Even with a p=none policy, aggregate reports help marketers detect if their domain is being spoofed. Without reporting, this critical visibility is lost.
• Importance of valid addresses: Always ensure the email addresses specified in the rua and ruf tags are active and capable of receiving mail. Misconfigured addresses lead to no DMARC reports being received.
• DMARC policy rollout: Properly staged DMARC implementation, starting with p=none and monitoring reports, is critical before moving to more restrictive policies. Learn more about when to use DMARC p=none, p=quarantine, or p=reject policies.

Key opinions

• Protocol non-compliance: Experts strongly believe that DMARC reports should not be sent unless explicit RUA/RUF addresses are provided in the DMARC record, as this is fundamental to the protocol.
• High suspicion of phishing: The primary concern for experts when an unexpected DMARC report arrives is that it's a phishing attempt, given the rise in sophisticated email fraud.
• Mailbox provider behavior: Experts assert that reputable mailbox providers like Google and Yahoo would not deviate from DMARC specifications by sending reports to unspecified addresses.
• Need for raw data: To properly analyze such an anomaly, experts require the full raw email, including headers and received lines, to uncover any hidden information or misconfigurations.

Key considerations

• Authentication standards: Adherence to DMARC, SPF, and DKIM standards is critical for email security and deliverability. Deviations can indicate issues or malicious activity. Understand a simple guide to DMARC, SPF, and DKIM.
• Forensic analysis: When an anomaly occurs, conducting a thorough forensic analysis of email headers can reveal crucial details about the sender, routing, and potential tampering.
• DMARC report interpretation: Even for seemingly legitimate reports, expertise is required to interpret them correctly, especially when dealing with DMARC reports from Google and Yahoo.
• Industry trends: Staying updated on current phishing trends and email security threats is vital for identifying suspicious activity that might masquerade as legitimate DMARC communication. Word to the Wise provides valuable insights into these trends.

Key findings

• Explicit RUA/RUF requirement: RFC 7489 states that reporting URIs (via RUA or RUF tags) are necessary for Mailbox Providers to send DMARC reports to domain owners. Without these, no reports are generated.
• Optional tags, mandatory for reports: While the RUA and RUF tags themselves are syntactically optional in a DMARC record, their absence means no reports will be received. A DMARC record can exist without them, but it won't yield monitoring data.
• Mailto: URI scheme: The DMARC specification requires that reporting addresses within the RUA/RUF tags must use the mailto: URI scheme to specify the recipient email address.
• Report content and format: Documentation outlines the standardized XML format for aggregate reports and the structure of forensic (sample) reports, ensuring consistency across different reporting entities.

Key considerations

• Strict adherence to RFCs: When configuring DMARC, always refer to the official RFC documentation to ensure correct syntax and implementation, as even minor errors can prevent proper reporting or authentication. Understanding what RFC 5322 says vs. what actually works is important.
• Security implications of RUF: While valuable for troubleshooting, forensic (RUF) reports contain sensitive email content. Documentation advises caution regarding their use due to privacy and data security concerns.
• Monitoring policy evolution: RFCs provide the foundation, but Mailbox Providers' interpretations and additional requirements (like those from Gmail and Yahoo) can evolve. Understanding and troubleshooting DMARC reports from Google and Yahoo is crucial.
• Domain verification for external reporting: If reporting addresses are on a different domain than the DMARC record, the recipient domain needs a DMARC record authorizing the receiving of reports. This is critical for services that provide DMARC monitoring. DuoCircle explains external domain verification for DMARC reporting.