Summary
Understanding why Sender Policy Framework (SPF) appears to pass in email headers but fails in DMARC aggregate reports or Google Postmaster Tools (GPT) can be a perplexing issue, especially when using platforms like Salesforce Marketing Cloud (SFMC). This discrepancy often indicates an underlying SPF alignment problem, rather than a direct SPF record failure. It's a common scenario where the technical nuances of email authentication, particularly how different domains are evaluated, can lead to confusion and concern over deliverability and sender reputation.
Key findings
- Authentication discrepancy: SPF can pass at the header level for the Mail From (return-path) domain, yet fail DMARC's alignment check for the From header domain.
- SFMC bounce domain behavior: Salesforce Marketing Cloud's Sender Authentication Package (SAP) is designed for the bounce domain to match the SAP domain, which is typically a subdomain, and not necessarily your primary brand domain. This is expected behavior.
- DMARC reporting: DMARC aggregate reports provide a comprehensive view of authentication results, including alignment, which may reveal SPF failures that are not apparent from simply inspecting email headers.
- Google Postmaster Tools (GPT): Different versions or interpretations within GPT (old vs. new dashboards) can display varying SPF pass rates, leading to confusion. These tools are increasingly focused on alignment.
- Sender reputation impact: A drop in sender reputation (e.g., from High to Medium) can prompt deeper investigation into such authentication anomalies, even if they've existed for some time.
Key considerations
- Validate SPF alignment: The primary focus should be on SPF alignment rather than just an SPF pass. This is where the domain in the Mail From address must align with the domain in the From header.
- Review DMARC reports: Utilize your DMARC aggregate reports to get accurate authentication data from mail providers. These reports will clearly indicate SPF alignment failures.
- Understand SFMC setup: Confirm that your SPF record in SFMC is correctly configured for your SAP domain and allows for relaxed alignment if a subdomain is used for bounces.
- Check subdomains: Ensure that the SPF domain for custom SAP domains is properly set at the subdomain level, which is standard for SFMC clients. This is crucial for resolving SPF failure.
- Seek expert advice: If you're still confused, consider consulting an expert or using a dedicated email authentication tool to analyze your headers and DMARC reports.
- Fundamental understanding: A good grasp of the basics of DMARC, SPF, and DKIM will help in diagnosing these complex issues.
What email marketers say
Email marketers often find themselves in a challenging position when dealing with SPF authentication within Salesforce Marketing Cloud. They observe that SPF appears to pass in immediate header checks, yet DMARC aggregate reports, which are crucial for compliance and deliverability, indicate a 0% pass rate. This discrepancy leads to a dilemma: should they push back on their ESP, or is there a subtle configuration detail they're missing? The core of the confusion often lies in the difference between a direct SPF pass and SPF alignment as required by DMARC.
Key opinions
- Alignment issues: Many marketers suspect SPF non-alignment as the primary cause, where SPF passes on the ESP's sender domain but not on the client's aligned domain.
- Conflicting tool data: There's frustration with differing reports from various tools, such as older Google Postmaster Tools showing failures while newer dashboards indicate everything is fine.
- SFMC's SAP behavior: Marketers acknowledge SFMC's explanation that the bounce domain (which is also the SPF domain) is designed to match the SAP domain, not necessarily the primary brand domain.
- BIMI consideration: The presence of BIMI setup suggests authentication should be solid, making SPF failures more puzzling.
- Impact on reputation: A drop in sender reputation prompts marketers to re-evaluate even long-standing configurations.
Key considerations
- Scrutinize DMARC reports: DMARC aggregate reports are the most reliable source for understanding SPF alignment issues, as they show how receiving mail servers interpret your authentication.
- Understand domain alignment: Educate yourself on the distinction between an SPF pass for the Mail From domain and DMARC's requirement for alignment with the From header.
- Monitor GPT: Keep an eye on Google Postmaster Tools V2 for its evolving reporting, as it reflects how Google evaluates your sender reputation.
- Collaborate with ESP: While SFMC's explanation for bounce domains is accurate, work with their support to ensure your specific setup aligns with DMARC best practices.
Marketer view
Email marketer from Email Geeks observes that SPF alignment issues are very common, particularly with the new requirements from Gmail. They've noticed discrepancies where older Postmaster Tools show SPF passing, but new dashboards reflect failures due to alignment. This indicates a shift in how mailbox providers evaluate authentication, prioritizing alignment for better security and deliverability. It's crucial for senders to adapt their understanding and monitoring.
Marketer view
A deliverability specialist from Salesforce Ben advises that while SPF and DKIM are foundational, their proper implementation needs to consider DMARC alignment. Simply having SPF pass on the technical sender domain isn't enough; it must align with the visible From domain for full authentication benefit. This is a common pitfall for marketers.
What the experts say
For email deliverability experts, the scenario of SPF appearing to pass but DMARC reports showing failures in Salesforce Marketing Cloud immediately brings SPF alignment to the forefront. Experts delve into the technical configuration of SFMC's Sender Authentication Package (SAP), the role of bounce domains, and the implications of different DMARC reporting methods. They offer systematic troubleshooting approaches to pinpoint whether the issue is a genuine misconfiguration or a reporting anomaly related to how SFMC handles subdomains for authentication.
Key opinions
- Unaligned pass: The most probable cause is an unaligned SPF pass, where the Mail From domain passes SPF but doesn't align with the From header domain for DMARC.
- SFMC subdomain structure: SFMC's use of a subdomain for SPF (bounce domain) is standard, relying on DMARC's relaxed alignment. If configured correctly, this should not be an issue.
- DMARC data accuracy: DMARC aggregate reports are considered the definitive source for authentication and alignment status, often revealing issues that direct header checks or older tools might miss.
- Configuration points: Potential failure points include different Marketing Cloud IDs (MIDs) or variations in IP configurations if multiple are used.
- GPT interpretation: Older GPT versions might not accurately reflect how a domain is being used in SFMC's standard configuration, leading to misleading 0% pass rates.
Key considerations
- Examine headers and RUA reports: Always consult email headers and DMARC RUA reports for precise details on Sender From, Mail From, and SPF alignment.
- Subdomain SPF alignment: Confirm that the SPF record for your SFMC subdomain is correctly set up for relaxed alignment (where the subdomain matches the organizational domain of the From header).
- Test all business units/MIDs: If multiple child accounts or business units are used, ensure the return-path domain configuration is consistent across all. This helps troubleshoot SPF and DMARC settings.
- Distinguish TempError: Be aware of SPF TempError in DMARC reports, which signifies a temporary DNS issue, distinct from an alignment failure.
Expert view
Deliverability expert from Email Geeks suggests that SPF pass in headers versus 0% pass in DMARC data likely indicates an unaligned pass. This means SPF itself might technically validate the sending IP, but the domain used for SPF authentication (the Mail From) doesn't align with the domain in the visible From header, causing DMARC to fail. This distinction is crucial for understanding the problem.
Expert view
SpamResource.com expert notes that many SPF failures in DMARC reports are not due to invalid SPF records but rather a lack of alignment. They advise that organizations must configure their email sending platforms, especially ESPs, to ensure that the domain authenticated by SPF matches or is a subdomain of the From header domain. Without this, DMARC will not pass SPF.
What the documentation says
Technical documentation for email authentication standards like SPF and DMARC provides the foundational understanding necessary to diagnose complex issues where SPF appears to pass but DMARC reports show failures. These documents define how SPF works at a granular level, differentiate between the various email header fields, and, most critically, explain the concept of 'alignment' that DMARC enforces. Understanding these specifications is key to resolving seemingly contradictory authentication results from email service providers like SFMC.
Key findings
- SPF validation scope: SPF authenticates the domain in the Mail From address (also known as Return-Path or Envelope From), ensuring the sending IP is authorized by that domain's SPF record.
- DMARC alignment requirement: For DMARC to pass SPF, the Mail From domain must align with the RFC 5322 From header domain, either strictly (exact match) or relaxed (subdomain match).
- ESP configurations: Email Service Providers frequently use bounce subdomains, necessitating relaxed SPF alignment to ensure DMARC passes for branded emails.
- DNS lookup limits: SPF records have a 10 DNS lookup limit. Exceeding this, typically due to too many include mechanisms, will cause an SPF PermError.
- DMARC reports detail: DMARC aggregate reports (RUA) provide detailed XML data on SPF and DKIM authentication results, including their alignment status and the policy applied by receiving servers. These reports are essential for understanding DMARC failures.
Key considerations
- Correct SPF record: Ensure your SPF record is correctly formatted and includes all authorized sending IPs or domains, especially those used by SFMC for your Mail From domain.
- Monitor DNS lookups: Regularly check your SPF record for exceeding the 10 DNS lookup limit, as this can cause a PermError and lead to SPF failures, particularly for Microsoft recipients due to their hidden SPF DNS timeout.
- DMARC policy application: The chosen DMARC policy (p=none, p=quarantine, or p=reject) dictates how receiving servers handle emails that fail DMARC, including those with SPF alignment issues. Review DMARC tags and their meanings.
- Domain selection: For SFMC, ensure the From header domain in your emails is correctly associated with your SAP configuration to facilitate proper alignment.
Technical article
The DMARC.org documentation explains that a DMARC 'pass' requires at least one of SPF or DKIM to pass AND to be in 'alignment' with the RFC 5322 From header domain. This means that an SPF record can technically pass for the Mail From domain, but if that Mail From domain doesn't align with the organizational domain of the From header, DMARC will still report an SPF failure for alignment.
Technical article
RFC 7208 (SPF) specifies that SPF primarily validates the 'Envelope From' address. It checks whether the IP address sending the email is authorized by the domain in this 'Envelope From' address. This is a foundational check, separate from the DMARC alignment requirement. Therefore, an SPF pass in headers confirms this specific check, not necessarily DMARC compliance.
Related resources
7 resources
Related pages
Why does DMARC authentication fail when SPF and DKIM pass, and how can it be fixed?
Why does SPF pass in headers but not Google Postmaster Tools, and what are domain alignment best practices?
How do I troubleshoot and fix SPF and DMARC settings for email deliverability issues?
How to fix SPF failure when return path and sender from addresses are different in SFMC?
How to troubleshoot SPF failures in Google Postmaster Tools and improve email delivery?
Why do SPF and DKIM failures sometimes occur despite correct setup?
A simple guide to DMARC, SPF, and DKIM
Why your emails fail at Microsoft: the hidden SPF DNS timeout
Demystifying the SPF TempError in your DMARC reports
Ultimate guide to Google Postmaster Tools V2
