Summary
When using email deliverability platforms like Validity, it can be confusing to see SPF (Sender Policy Framework) authentication show 0% alignment even when the SPF check itself passes. This discrepancy highlights a critical distinction in email authentication: the difference between an SPF pass and SPF alignment. While SPF passing simply means the sending IP address is authorized by the domain in the envelope From (Mail From) address, SPF alignment, which is crucial for DMARC (Domain-based Message Authentication, Reporting, and Conformance), requires the envelope From domain to align with the RFC5322 From header domain. Many Email Service Providers (ESPs) often use their own infrastructure or subdomains in the envelope From address by default, leading to this non-alignment, unless specific configurations are made by the sender.
Key findings
- Distinction: SPF passing means the sending server's IP is authorized by the Mail From domain. SPF alignment, however, requires the Mail From domain to match or be a subdomain of the From header domain.
- DMARC dependency: For DMARC to pass SPF, both SPF authentication and SPF alignment must succeed. If SPF passes but does not align, it contributes to a DMARC failure unless DKIM passes and aligns.
- Common ESP setup: Many ESPs, such as Mailchimp, Constant Contact, Sendgrid, Amazon SES, and Iterable using SparkPost, often use their own return-path (envelope From) domain by default, leading to SPF passing for their domain but not aligning with the sender's domain. Custom configurations are often required for alignment.
- Auth-results headers: Analyzing the Auth-results header in emails provides detailed insights into SPF authentication and alignment results, helping to diagnose issues.
Key considerations
- Understand alignment rules: Recognize that SPF passing and alignment are distinct. A message can pass SPF but fail DMARC if the domains do not align, as explained further in what it means when SPF is not aligned.
- Configure ESPs for alignment: Work with your ESP to configure a custom return path or dedicated sending domain to ensure the Mail From domain aligns with your From header domain.
- Leverage DKIM: Ensure DKIM (DomainKeys Identified Mail) is properly configured and aligned. If DKIM passes and aligns, DMARC will still pass, even if SPF does not align. This is a common solution for DMARC authentication failures when SPF and DKIM pass.
- Monitor DMARC reports: Regularly review DMARC aggregate and forensic reports to identify specific instances of SPF and DKIM alignment failures. For further guidance on fixing alignment issues, refer to this article on GoDMARC.
What email marketers say
Email marketers often face challenges with SPF alignment, particularly when using third-party email service providers. They might observe that SPF passes authentication checks, yet their DMARC reports or monitoring tools indicate 0% SPF alignment. This situation commonly arises because many ESPs, by default, send emails using their own bounce domains in the envelope From address, which does not match the sender's From header domain. Marketers frequently inquire whether this discrepancy is normal or indicative of a misconfiguration, highlighting a common misunderstanding that an SPF pass automatically implies DMARC alignment.
Key opinions
- ESPs and alignment: It is widely noted that many popular ESPs, such as Mailchimp and Constant Contact, typically result in 0% SPF alignment unless specific configurations are applied. This includes platforms like Sendgrid, Amazon SES, and Iterable when using services like SparkPost.
- Separation of pass and alignment: There's a general understanding among marketers that passing SPF is not the same as having SPF alignment. An email can successfully pass SPF authentication but still fail alignment, which is critical for DMARC.
- DMARC reliance on DKIM: Marketers acknowledge that DMARC can still pass if DKIM is properly configured and aligned, even if SPF alignment is at 0%.
- Provider-specific solutions: Some ESPs, like ActiveCampaign, have implemented features to enable full SPF alignment for their users, which can greatly simplify DMARC compliance.
Key considerations
- Verify envelope domain: Always check the envelope domain (Mail From) to understand why SPF might be passing but not aligning with your sending domain. This is essential for troubleshooting issues such as SPF failures reported by Google Postmaster Tools.
- Prioritize DMARC compliance: Even with SPF passing but not aligning, ensure DMARC passes by securing DKIM alignment. This is crucial as bad SPF alignment can still affect deliverability.
- Consult ESP documentation: Refer to your ESP's documentation or support for specific instructions on how to achieve SPF and DKIM alignment, as this can vary significantly between providers. For instance, discussions on community forums like Spiceworks Community often highlight provider-specific challenges.
Marketer view
Marketer from Email Geeks observes that Validity is showing 0% SPF alignment for their domain despite SPF passing, finding this behavior confusing and possibly incorrect. This indicates a common point of confusion among senders who might assume that a passing SPF record automatically guarantees full DMARC compliance.The observation highlights the need for a clearer understanding of how email authentication tools interpret and report different aspects of SPF, specifically distinguishing between authentication success and domain alignment. It also suggests that some platforms' reporting might not immediately clarify this nuance for the end-user.
Marketer view
Marketer from Email Geeks questions whether it is possible to see 0% SPF alignment while simultaneously having 100% SPF passing. This directly addresses the core misunderstanding between the two concepts, illustrating that a sending domain can be authorized (SPF pass) without its envelope domain aligning with the visible From header.This inquiry underscores the complexity of email authentication for those who are not deeply immersed in its technical specifications, where separate mechanisms govern SPF validation and DMARC alignment checks. It's a common scenario for users of third-party ESPs.
What the experts say
Experts in email deliverability consistently clarify that SPF passing and SPF alignment are distinct concepts. While an email may pass SPF authentication because its sending IP is listed in the Mail From domain's SPF record, DMARC requires alignment between this Mail From domain and the visible From header domain. If an ESP uses its own domain for the Mail From address by default, SPF will pass but alignment will fail, a normal occurrence unless specific sender configurations are implemented to achieve alignment or DKIM provides the necessary DMARC pass.
Key opinions
- Fundamental distinction: Experts consistently emphasize that SPF passing and SPF alignment are distinct operations. An email can pass SPF authentication (meaning the sending IP is authorized for the envelope sender) but still fail SPF alignment for DMARC if the envelope sender domain does not align with the header From domain.
- ESPs and default non-alignment: It is a known characteristic of many ESPs, including Mailchimp, Constant Contact, Sendgrid, and Amazon SES, that their default sending configurations will lead to 0% SPF alignment unless senders explicitly configure custom return paths or use their own dedicated sending domains.
- DMARC's flexibility: DMARC only requires one of SPF or DKIM to pass AND align. Therefore, if DKIM is properly configured and aligned, DMARC will pass, even if SPF alignment is at 0%. This offers a fallback mechanism.
- Importance of headers: Analyzing the Auth-results header is crucial for understanding the specific reasons behind SPF passing and alignment status, as it contains the definitive authentication results.
Key considerations
- Inspect the envelope domain: Always identify the Mail From (envelope) domain used by your ESP. This is the domain against which SPF checks are performed, and it must align with your From header domain for SPF DMARC alignment.
- Understand DMARC authentication flow: Familiarize yourself with the interplay between DMARC, SPF, and DKIM, particularly the alignment requirement for DMARC to pass. This provides a foundational understanding to resolve authentication issues.
- Leverage DMARC reports for insights: Utilize DMARC aggregate reports to pinpoint the domains and sources that are experiencing SPF alignment failures. This data is critical for targeted troubleshooting and ensuring your emails meet authentication standards. For more context, see how SPF alignment impacts deliverability.
- Seek specific ESP guidance: While general principles apply, specific steps to achieve SPF alignment vary by ESP. Consulting your ESP's documentation or support for their recommended alignment configurations is crucial for successful implementation. SpamResource often provides valuable insights into these technical nuances.
Expert view
Expert from Email Geeks explains that 0% SPF alignment on a platform like Validity is indeed possible, and its occurrence largely depends on the sender's origin and the specific envelope domain used. This highlights the variability in sending practices across different email infrastructures and how they interact with authentication protocols.The envelope domain (also known as the Mail From or bounce address) is the key element SPF checks against, and if an ESP uses its own domain for this, SPF will pass for that domain, but it will not align with the client's From header domain unless explicitly configured.
Expert view
Expert from Email Geeks emphasizes the critical importance of knowing the envelope domain when troubleshooting SPF alignment issues. The envelope domain is fundamental because SPF performs its checks against this specific domain, not the visible From header domain.This distinction is often a source of confusion for senders. Understanding which domain is in the envelope is the first step to determining if it aligns with the From header and thus if SPF alignment for DMARC will pass.
What the documentation says
Official email authentication documentation, including RFCs for SPF, DKIM, and DMARC, clearly defines SPF alignment as a separate and crucial component for DMARC validation. It specifies that for SPF to align, the domain in the RFC5321.MailFrom address (envelope From) must match or be a subdomain of the RFC5322.From address (header From). This requirement is distinct from merely passing the SPF check, which only verifies the sending IP against the envelope From domain's SPF record. Documentation also outlines 'relaxed' and 'strict' alignment modes, offering flexibility in how this match is enforced.
Key findings
- RFC5321 vs RFC5322: SPF primarily protects the RFC5321.MailFrom address (envelope From), which is used for bounce messages. DMARC alignment, however, links this to the RFC5322.From header (visible From address).
- Alignment requirement: For SPF to achieve DMARC alignment, the domain in the Mail From address must be identical to (strict alignment) or a subdomain of (relaxed alignment) the domain in the From header.
- DMARC's role: DMARC builds upon SPF and DKIM by adding the alignment requirement, ensuring that the domains being authenticated are the ones users see and trust. If SPF passes but does not align, DMARC will treat it as a failure for DMARC authentication, unless DKIM aligns.
- Reporting: DMARC reports provide essential feedback on SPF and DKIM authentication and alignment results, enabling domain owners to identify and rectify misconfigurations. These reports are detailed by various DMARC tags.
Key considerations
- Consult DMARC RFC: For a comprehensive understanding, refer to DMARC.org's overview and RFC 7489, which details DMARC's alignment requirements for both SPF and DKIM. This foundational knowledge is crucial for proper implementation.
- Implement DMARC policies carefully: When setting a DMARC policy (e.g., p=quarantine or p=reject), ensure that your SPF and DKIM alignment is robust to avoid unintended mail delivery issues. Learn more about the simple guide to DMARC, SPF, and DKIM.
- Leverage reporting for compliance: The reporting capabilities defined in DMARC are vital for continuous monitoring and adjustment, allowing domain owners to quickly identify any sources that are failing authentication or alignment for their domain.
Technical article
RFC 7489 documentation states that DMARC builds upon existing SPF and DKIM protocols by introducing a crucial 'domain alignment' requirement. This means that for DMARC to pass, the domain that passed SPF or DKIM authentication must be aligned with the domain presented in the visible From header of the email.This additional layer ensures that the authenticated sender is genuinely associated with the brand visible to the recipient, significantly enhancing protection against email spoofing and phishing attacks. It's a key distinction that elevates DMARC beyond simple authentication.
Technical article
RFC 7489 documentation specifies that for SPF alignment, the domain found in the RFC5321.MailFrom address (the envelope sender) must match or be a subdomain of the domain in the RFC5322.From address (the header From). This defines the exact technical relationship required for alignment.This rule ensures that the domain used for SPF validation is directly related to the domain that the email purports to be from. Without this relationship, even if SPF passes, it does not contribute to DMARC's pass criteria, highlighting why 0% SPF alignment can occur.
Related resources
4 resources
Related pages
What does it mean when SPF is not aligned in a DMARC report and how does it affect deliverability?
Why does DMARC authentication fail when SPF and DKIM pass, and how can it be fixed?
Why does Google Postmaster Tools show 0% SPF success rate when SPF, DKIM, and DMARC pass?
What causes SPF authentication to fluctuate between 100% and 0% in Google Postmaster Tools?
A simple guide to DMARC, SPF, and DKIM
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