Why does SPF alignment show as 0% on Validity, even when SPF passes?

Summary

SPF alignment, as reported by services like Validity, often shows 0% even when SPF passes because the domain used for SPF authentication (the 'MAIL FROM' or envelope sender) doesn't match the domain in the 'From' header. This is a common scenario when using third-party sending services or ESPs (like Mailchimp, Constant Contact, Sendgrid, and Amazon SES) that utilize their own infrastructure and domains for sending on behalf of customers. While SPF can pass based on the ESP's domain, DMARC requires alignment between the authenticated domain and the 'From' header domain to ensure the email truly originates from the claimed sender. DMARC can pass with either SPF or DKIM alignment. If DKIM is used, the DKIM domain also needs to align for DMARC to pass. Solutions involve configuring custom MAIL FROM settings, using a custom return-path, or implementing DKIM to achieve proper alignment.

Key findings

  • Domain Mismatch: The 'MAIL FROM' domain (used for SPF) doesn't match the 'From' header domain.
  • Third-Party Senders: ESPs and third-party services commonly use their own domains for the 'MAIL FROM' address.
  • DMARC Requirement: DMARC requires SPF alignment (or DKIM alignment) for proper authentication and deliverability.
  • Passing vs. Aligning: SPF can pass based on the sending server's domain without aligning with the sender's domain in the 'From' header.
  • DKIM as Alternative: DKIM can be used for DMARC compliance if it passes and aligns, even if SPF fails alignment.

Key considerations

  • Check Domains: Verify the 'MAIL FROM' and 'From' domains and ensure they are configured correctly.
  • Custom Configuration: Configure custom MAIL FROM settings or a custom return-path domain with your ESP to align with your sending domain.
  • Implement DKIM: Implement DKIM signing using your own domain to achieve alignment, especially if SPF alignment is difficult.
  • Understand DMARC: Grasp how DMARC uses SPF and DKIM alignment to determine email authenticity and improve deliverability.
  • ESP-Specifics: Investigate how specific ESPs handle SPF, DKIM, and DMARC alignment, and adjust settings accordingly.
  • Alignment Type: Understand if your DMARC policy is using strict or relaxed alignment. Strict alignment requires an exact domain match while relaxed alignment allows for subdomains.

What email marketers say
9Marketer opinions

SPF alignment failures, despite SPF passing, primarily occur because the domain used for SPF authentication (MAIL FROM or return-path) does not match the domain in the 'From' header. This discrepancy is common when using third-party sending services or ESPs, which often use their own infrastructure and domains for sending emails on behalf of their customers. Although SPF can pass based on the ESP's domain, it doesn't align with the sender's domain, impacting DMARC compliance. Solutions involve configuring custom MAIL FROM settings, using a custom return-path domain, or implementing DKIM.

Key opinions

  • Domain Mismatch: The 'MAIL FROM' domain (used for SPF) differs from the 'From' header domain.
  • Third-Party Senders: ESPs and third-party services often use their own domains for 'MAIL FROM'.
  • DMARC Requirement: DMARC requires SPF alignment for proper authentication.
  • Passing vs. Aligning: SPF can pass based on the sending server's domain without aligning with the sender's domain.
  • Shared Infrastructure: Using shared sending infrastructure can cause alignment issues due to different 'MAIL FROM' domains.

Key considerations

  • Check Domains: Verify the 'MAIL FROM' and 'From' domains to ensure they match or are appropriately related.
  • Custom Configuration: Configure custom 'MAIL FROM' settings or a custom return-path domain with your ESP.
  • Implement DKIM: Consider implementing DKIM for domain authentication as an alternative or complementary method.
  • DMARC Impact: Understand that SPF alignment issues can negatively impact DMARC compliance and email deliverability.
  • ESP Defaults: Be aware that ESP default settings might not provide SPF alignment and require manual configuration.
Marketer view

Email marketer from GlockApps responds that SPF alignment issues can occur because the return-path domain is different from the from domain. They suggest checking the 'return-path' and 'from' domains to ensure they match, or configure a custom return-path domain to align with the 'from' domain.

April 2024 - GlockApps
Marketer view

Email marketer from Sendgrid suggests that the most common reason for SPF passing but failing to align is the use of a shared sending infrastructure where the MAIL FROM domain is different from the From domain. They suggest using a custom MAIL FROM domain or DKIM as potential solutions.

November 2024 - Sendgrid
Marketer view

Email marketer from URIports notes that shared sending infrastructures use different domains in the MAIL FROM header. Therefore, the SPF check passes based on the IP address of the sending server used by the sending service provider. The email fails the SPF alignment check because it does not match the domain in the From header.

January 2023 - URIports
Marketer view

Email marketer from Email on Acid shares that 0% SPF alignment often occurs when using third-party sending services where the 'MAIL FROM' domain is different from the sender's domain. This is because these services use their own infrastructure for sending, affecting SPF alignment.

April 2024 - Email on Acid
Marketer view

Email marketer from Stackoverflow comments on why SPF alignment fails is because SPF is evaluated on the 'MAIL FROM' address and DMARC often requires alignment with the 'From' header. If these don't match, SPF passes but fails to align for DMARC purposes.

November 2021 - Stackoverflow
Marketer view

Email marketer from Reddit mentions that when using third-party senders, they often use their own domains for the 'MAIL FROM' address. This allows them to manage their reputation but results in SPF passing based on their domain, not aligning with yours.

September 2022 - Reddit
Marketer view

Email marketer from Email Marketing Forum adds that many ESPs send emails on behalf of their customers, and the SPF record that passes is for the ESP, not the customer's domain, which causes SPF to pass, but not align with the customer's 'From' domain. Setting up a custom domain or DKIM is suggested.

April 2022 - Email Marketing Forum
Marketer view

Email marketer from Mailjet states that SPF alignment issues often arise when ESPs use a subdomain or a different domain for the 'MAIL FROM' address. While SPF can still pass based on the ESP's domain, it won't align with the sender's domain unless properly configured with custom MAIL FROM settings.

December 2021 - Mailjet
Marketer view

Email marketer from EasyDMARC highlights that SPF alignment fails when the 'MAIL FROM' domain doesn't match the 'From' domain. Even if the SPF check passes based on the sending server's domain, it won't align with your domain, impacting DMARC compliance.

July 2024 - EasyDMARC

What the experts say
6Expert opinions

SPF alignment failures, even when SPF passes, stem from the domain used for SPF authentication (MAIL FROM) not matching the domain in the 'From' header. This is common with ESPs like Mailchimp, Constant Contact, Sendgrid, and Amazon SES, unless configured otherwise. SPF authenticates the sending server, but DMARC requires the domains to align. DMARC can pass with either aligned SPF or aligned DKIM. If DKIM passes but the DKIM domain doesn't align, DMARC will fail. The ultimate goal of alignment is to ensure that the authorized sending domain matches the domain displayed to the recipient.

Key opinions

  • Domain Mismatch: The 'MAIL FROM' domain (SPF) doesn't match the 'From' header domain.
  • ESP Defaults: Many ESPs, by default, cause SPF to pass without alignment.
  • DMARC Requirement: DMARC requires either SPF or DKIM to pass *and* align.
  • SPF vs. DMARC: SPF only authenticates the sending server, while DMARC authenticates the domain presented to the recipient.
  • DKIM's Role: DKIM can be used for DMARC compliance if it passes and aligns, even if SPF fails alignment.

Key considerations

  • Check Configuration: Verify 'MAIL FROM' and 'From' domains and configure ESPs for alignment.
  • DMARC Requirements: Understand DMARC's need for either SPF or DKIM alignment.
  • DKIM Setup: Ensure DKIM is properly configured and aligned if relying on it for DMARC compliance.
  • ESP-Specifics: Investigate how specific ESPs handle SPF and DKIM alignment.
  • Overall Strategy: Develop a holistic email authentication strategy encompassing SPF, DKIM, and DMARC.
Expert view

Expert from Spam Resource explains that SPF authenticates the server sending the email but doesn't necessarily align with the domain in the 'From' header, which DMARC requires. The domains in the 'MAIL FROM' and 'From' header must match or be related for proper alignment.

January 2022 - Spam Resource
Expert view

Expert from Email Geeks clarifies that SPF needs to pass and be aligned for DMARC to pass, but DMARC can also pass if DKIM passes and is aligned independently of SPF. DMARC only needs one (SPF or DKIM) to pass and align in order to pass.

December 2023 - Email Geeks
Expert view

Expert from Email Geeks explains that if the DKIM domain (`d=`) doesn't align, DKIM can pass while DMARC fails.

August 2023 - Email Geeks
Expert view

Expert from Email Geeks explains that mail from several ESPs, including Mailchimp and Constant Contact, often shows 0% SPF alignment. Also unless explicitly configured, Sendgrid and Amazon SES, will also show this.

November 2023 - Email Geeks
Expert view

Expert from Word to the Wise explains that the reason you want alignment is to pass DMARC. SPF alignment is about making sure that the domain in the From: header is the same as the domain that was authorized to send the mail.

November 2021 - Word to the Wise
Expert view

Expert from Email Geeks confirms that SPF can pass without alignment because passing and aligning are two different things.

July 2021 - Email Geeks

What the documentation says
5Technical articles

SPF alignment fails when the domain in the 'MAIL FROM' (envelope sender or return-path) address doesn't match the domain in the 'From' header. This mismatch prevents DMARC from properly authenticating email using SPF, even if SPF passes based on the 'MAIL FROM' domain. Third-party email services often cause this issue by using their own 'MAIL FROM' domains. Alignment requires an exact match or subdomain relationship between the domains, depending on DMARC's alignment mode.

Key findings

  • Domain Mismatch: 'MAIL FROM' domain differs from 'From' header domain.
  • DMARC Requirement: SPF alignment is necessary for DMARC authentication with SPF.
  • Third-Party Impact: Third-party services often cause alignment failures due to their 'MAIL FROM' domains.
  • Alignment Modes: DMARC supports strict or relaxed alignment, requiring an exact match or subdomain relationship.

Key considerations

  • Check Domains: Verify the 'MAIL FROM' and 'From' domains for consistency.
  • Configure Alignment: Ensure domains align based on DMARC alignment mode (strict or relaxed).
  • Understand DMARC: Comprehend DMARC's reliance on alignment for effective authentication.
  • Third-Party Settings: Review configurations of third-party email services to achieve proper SPF alignment.
Technical article

Documentation from AuthSMTP explains that the domain in the MAIL FROM and From header must match to satisfy SPF Alignment. This means that if your SPF record is configured correctly and SPF passes but your SPF alignment is still 0%, the domain in your From and MAIL FROM headers do not match, causing SPF alignment to fail.

July 2021 - AuthSMTP
Technical article

Documentation from DMARC.org explains that for SPF to align, the domain in the 'MAIL FROM' (also known as the envelope from or return-path) must exactly match the organizational domain in the 'From' header, or be a subdomain of it, depending on whether 'strict' or 'relaxed' alignment is used. If there's no match, SPF will pass but not align.

September 2021 - DMARC.org
Technical article

Documentation from RFC 4408 outlines that SPF alignment requires the domain in the 'MAIL FROM' to match the domain used to evaluate DMARC. A discrepancy leads to alignment failure even if SPF passes based on the 'MAIL FROM' domain.

September 2023 - RFC 4408
Technical article

Documentation from Microsoft says that if you are using a third-party email service, the MAIL FROM address might be different from your domain. This can result in SPF passing based on the third-party service's SPF record but not aligning with your own domain, impacting DMARC compliance.

July 2023 - Microsoft
Technical article

Documentation from Google Workspace Admin Help explains that SPF alignment fails if the domain used in the 'MAIL FROM' (envelope sender) address does not match the domain in the 'From' header address. Even if SPF passes based on the 'MAIL FROM' domain, alignment is necessary for DMARC to use SPF for authentication.

May 2023 - Google Workspace Admin Help