Summary
Changing a DMARC policy from 'none' to 'quarantine' (p=quarantine) often leads to legitimate emails being sent to the spam folder, particularly when underlying email authentication mechanisms are not perfectly aligned. This issue primarily stems from DMARC's enforcement actions, which instruct recipient mail servers to treat emails failing DMARC validation with increased scrutiny. When SPF (Sender Policy Framework) or DKIM (DomainKeys Identified Mail) records are not correctly set up, or if their domains do not align with the 'From' header domain, emails will fail DMARC authentication. A 'softfail' SPF record, combined with misalignment, signals to receiving mail servers that while an email might not be outright fraudulent, it also isn't fully authenticated, prompting a 'quarantine' action (moving to spam or junk).
Key findings
- DMARC enforcement: A policy of p=quarantine instructs receiving mail servers to place emails failing DMARC authentication into the spam or junk folder.
- Alignment requirement: For DMARC to pass, either the SPF 'Return-Path' domain or the DKIM 'd=' tag domain must align with (be the same as, or a subdomain of) the 'From' header domain. If this alignment is missing, DMARC will fail, even if SPF and DKIM records technically pass.
- Softfail SPF: An SPF record at 'softfail' combined with DMARC's quarantine policy signals to mail servers that the email should be treated with suspicion if alignment also fails.
- Importance of DMARC reports: DMARC aggregate reports provide crucial visibility into which email streams are failing authentication and why, allowing senders to identify and correct issues before enforcing stricter policies.
Key considerations
- Pre-deployment analysis: Before switching to p=quarantine, it's essential to analyze DMARC reports (while on p=none) to ensure all legitimate email sources are correctly authenticating and aligning. This helps avoid unintended deliverability issues. Read more about when to use DMARC policies.
- Correcting SPF and DKIM: Ensure that all third-party sending services (ESPs, transactional email services, CRMs, etc.) are properly configured to send emails that pass both SPF and DKIM authentication and align with your 'From' domain. This often involves setting up custom DKIM keys and ensuring SPF records include all authorized sending IPs or domains.
- Understanding DMARC alignment: It's crucial to understand that SPF and DKIM can pass independently but still fail DMARC if their respective domains do not align with the 'From' domain. This is a common pitfall. A useful resource on this topic is Word to the Wise's DMARC primer.
- Iterative approach: Implementing DMARC (and transitioning to stricter policies) should be an iterative process, starting with p=none to gather data, then moving to p=quarantine gradually. Learn about safely transitioning your DMARC policy.
What email marketers say
Email marketers often face immediate and visible deliverability issues when transitioning their DMARC policy to 'quarantine' without fully understanding the intricacies of DMARC alignment. Many assume that merely passing SPF and DKIM is sufficient, overlooking the critical alignment component that DMARC introduces. The abrupt shift can lead to legitimate emails, such as transactional messages, landing in spam folders, causing significant disruption and a quick reversion to a 'none' policy.
Key opinions
- Initial confusion: Marketers frequently report that emails suddenly go to spam right after changing to a p=quarantine policy, leading to quick reversions without full diagnosis.
- Lack of DMARC report monitoring: Many marketers do not actively monitor DMARC aggregate reports, which are essential for identifying authentication failures and correcting issues before enforcing policies.
- Misunderstanding alignment: There's a common misconception that if SPF and DKIM records technically pass, DMARC will automatically pass. The critical aspect of domain alignment is often overlooked.
- Impact on deliverability: Unprepared implementation of p=quarantine can lead to significant deliverability issues, affecting crucial email streams like billing or customer service communications.
Key considerations
- Educate clients: It's vital to educate clients and stakeholders about DMARC's full implications, including the alignment requirements, before any policy changes are made.
- Verify SPF and DKIM setup: Prioritize verifying that all sending sources have correctly configured SPF and DKIM records, and critically, that these are set up for domain alignment. This is crucial to diagnose email deliverability issues.
- Analyze DMARC reports thoroughly: Use DMARC reports to identify every mail stream that is failing authentication or alignment before transitioning to stricter policies. This helps reveal unknown sending sources or misconfigurations. You can learn more about this on Kinsta's DMARC fail guide.
- Phased DMARC rollout: Advocate for a gradual DMARC implementation, starting with p=none to gather data, then moving cautiously to p=quarantine, and finally to p=reject once all legitimate traffic is aligned. This minimizes the risk of emails being blocked or sent to spam.
Email marketer from Email Geeks indicates that after they changed their DMARC policy to quarantine, emails from that domain immediately started going to the spam folder for their company accounts. This observation suggests a direct correlation between the policy change and the deliverability issue. They swiftly reverted the DMARC record back to 'none,' which then resolved the issue, confirming the policy change as the likely cause.
An email marketer from a deliverability forum shared their experience, stating that without proper DMARC alignment, moving to a quarantine policy essentially self-sabotages deliverability. They highlighted the importance of having SPF and DKIM correctly configured and aligned with the visible 'From' domain. They emphasized that even if SPF and DKIM pass individually, a DMARC failure due to misalignment will still trigger the quarantine policy, sending emails to spam.
What the experts say
Email deliverability experts consistently highlight that DMARC is a powerful protocol, but its implementation requires meticulous attention to detail, especially regarding SPF and DKIM alignment. They emphasize that simply passing SPF and DKIM authentication is insufficient for DMARC; true DMARC compliance hinges on the alignment of the authenticated domains with the email's 'From' header. Rushing to a 'quarantine' policy without verifying every legitimate email stream's alignment can lead to significant, self-inflicted deliverability issues, effectively 'shooting yourself in the deliverability'.
Key opinions
- DMARC alignment is critical: Experts stress that DMARC failures, even when SPF and DKIM pass, are almost always due to misalignment between the authenticated domains and the visible 'From' header domain. This is the core reason for emails going to spam under a 'quarantine' policy.
- Monitor DMARC reports: Daily monitoring of DMARC aggregate reports is non-negotiable for identifying failing mail streams and diagnosing alignment issues. This data is invaluable for safe DMARC deployment.
- DMARC complexity: DMARC is acknowledged as a complex protocol that can easily break email deliverability if not implemented correctly and carefully. It requires a deep understanding of email authentication beyond basic SPF/DKIM setup.
- Comprehensive mail stream audit: Before enforcing p=quarantine, organizations must identify and configure every third-party service sending email on their behalf to ensure DMARC compliance.
Key considerations
- Identify all sending services: Use DMARC aggregate reports to discover all legitimate email sources sending on behalf of your domain. Many organizations are surprised by the number of services they unknowingly use that send emails.
- Configure SPF/DKIM for alignment: Work with each third-party sender to ensure their SPF and DKIM configurations enable DMARC alignment. This typically involves using custom domains for DKIM signing or ensuring the SPF 'Return-Path' matches your 'From' domain. This is essential for fixing DMARC authentication failures.
- Avoid premature enforcement: Do not transition to p=quarantine or p=reject until DMARC reports show nearly 100% compliance for all legitimate traffic. This iterative process is crucial for preventing critical email deliverability issues. Read more on Email on Acid's guide to DMARC policy.
- Seek expert help: For complex environments or if technical expertise is lacking, outsourcing DMARC implementation to specialized firms can prevent significant deliverability disruptions. DMARC is more than just a DNS record; it's a domain-wide policy.
Expert from Email Geeks (wise_laura) clarifies that emails are likely failing DMARC because they are not aligned, even if SPF and DKIM technically pass. She states it's not enough for SPF and DKIM to simply pass authentication; they must also be in the same domain space as the visible 'From' address for DMARC to be successful. This highlights the crucial distinction between authentication and alignment.
Expert from Word to the Wise warns that implementing DMARC, particularly moving to enforcement policies like quarantine or reject, carries the risk of self-inflicting deliverability problems. He emphasizes that DMARC is designed to reveal email streams that are not properly authenticated and aligned, which can surprise companies. This means that previously undiscovered misconfigurations or unauthorized sending sources will become apparent when a quarantine policy is put in place.
What the documentation says
Official DMARC documentation and related RFCs (Request for Comments) define how DMARC policies like 'quarantine' are intended to function and the underlying mechanisms of SPF and DKIM alignment. The documentation clarifies that DMARC's primary goal is to provide domain owners with a mechanism to protect their domain from unauthorized use (spoofing) by instructing receiving mail servers how to handle emails that fail authentication and alignment checks. It explicitly states the requirements for alignment, emphasizing that both SPF and DKIM must align with the 'From' header domain, not just pass individually.
Key findings
- DMARC policy 'quarantine': The 'quarantine' policy (p=quarantine) directs recipient mail servers to accept an email that fails DMARC authentication but place it into the recipient's junk or spam folder, or flag it suspiciously.
- Domain alignment explained: For SPF alignment, the 'Return-Path' (Mail From) domain must match the 'From' header domain. For DKIM alignment, the 'd=' (signing) domain must match the 'From' header domain. A DMARC record requires at least one of these to align and pass authentication.
- Default alignment modes: The default alignment mode for both SPF and DKIM under DMARC is 'relaxed', meaning only the organizational domain (e.g., example.com for sub.example.com) needs to match. 'Strict' alignment requires an exact match, including subdomains.
- DMARC reports (RUA/RUF): DMARC provides aggregate (RUA) and forensic (RUF) reports to domain owners. These reports detail authentication and alignment failures, allowing for comprehensive monitoring and diagnosis of issues across all mail streams. You can read more about the list of DMARC tags and their meanings.
Key considerations
- Policy application: DMARC policies apply to the organizational domain specified in the DMARC record and any subdomains, unless explicitly overridden. This broad application means that all email-sending services for the domain must comply.
- Pre-authentication is key: Before publishing a DMARC record, or moving to stricter policies, ensure that SPF and DKIM are fully implemented and passing for all legitimate email sources. This foundational work is critical.
- Understanding aggregate reports: Leverage DMARC aggregate reports to gain visibility into which emails are passing or failing DMARC, and which sending sources are responsible. These reports are XML files that require a parser or DMARC monitoring service to be easily readable. Learn more about understanding and troubleshooting DMARC reports.
- Iterative deployment: The RFC recommends starting with p=none to gather data, then gradually moving to p=quarantine, and finally p=reject after all legitimate sources are confirmed to align and authenticate properly. More information can be found in the DMARC RFC 7489.
DMARC.org documentation explains that a DMARC policy of p=quarantine instructs recipient mail servers to accept emails that fail DMARC authentication, but place them into the recipient’s junk or spam folder. This policy is a step towards full enforcement and provides a safety net compared to outright rejection. It is intended to mitigate the risk of spoofing while allowing for further analysis by the recipient.
RFC 7489, which defines DMARC, clarifies that for an email to pass DMARC, it must pass either SPF or DKIM authentication, and the authenticated domain must align with the 'From' header domain. This alignment can be either 'relaxed' (matching organizational domains) or 'strict' (exact domain match). The RFC underscores that a failure in this alignment is a common reason for DMARC policy actions to be applied.
