Summary
DMARC failures despite passing SPF and DKIM in Sendgrid are primarily attributed to alignment issues. The 'From' domain must align with the SPF authenticated domain or DKIM signing domain. Common causes include SPF using Sendgrid's domain, DKIM using incorrect keys, or Sendgrid subuser misconfigurations. A p=reject policy necessitates domain alignment. Proper DNS configuration, reviewing DMARC policies, and analyzing DMARC reports are crucial for resolving these failures.
Key findings
- Alignment is Crucial: DMARC requires alignment between the 'From' domain and the SPF and DKIM domains. Misalignment is the primary reason for failures.
- Sendgrid-Specific Issues: When using Sendgrid, SPF might use Sendgrid's domain causing SPF alignment failure, and subuser settings can lead to misconfiguration.
- DKIM Key Integrity: DKIM signatures must be valid and signed with your domain's key. Incorrect or missing DKIM signatures result in failures.
- DMARC Policy Matters: A DMARC policy set to 'reject' requires stringent domain alignment to pass authentication.
- Importance of DNS Configuration: Properly configured DNS records for SPF and DKIM are essential for successful DMARC authentication.
- Reporting and Analysis: Analyzing DMARC reports helps identify specific authentication failures and alignment problems.
Key considerations
- Verify Alignment: Ensure the 'From' domain aligns with both SPF and DKIM records.
- Configure Sendgrid Correctly: Configure Sendgrid with custom DKIM signatures, a Return-Path aligning with your domain, and proper subuser settings.
- Review DNS: Examine DNS records for SPF and DKIM for correct setup and propagation.
- Check Key Publication: Verify publication of the correct public key in DNS for DKIM verification.
- Adjust DMARC Policy: Adapt the DMARC policy and reporting settings as needed, based on monitoring results.
- Monitor Reports: Regularly check and analyze DMARC reports to pinpoint and resolve authentication problems.
What email marketers say
12 marketer opinions
Even when SPF and DKIM pass, DMARC can fail due to alignment issues. Alignment means the 'From' domain must match the domains used for SPF and DKIM. Common causes include SPF using SendGrid's domain, DKIM signing with a different domain, or improper DNS configuration. Sendgrid subusers and DMARC record settings also contribute to DMARC failures. Reviewing DMARC reports helps diagnose problems.
Key opinions
- Alignment is Key: DMARC requires alignment between the 'From' domain and the domains used in SPF and DKIM. Mismatches cause DMARC to fail.
- Sendgrid's Domain Usage: When using SendGrid, SPF might use SendGrid's domain, causing SPF alignment issues. Use your own domain for SPF.
- DKIM Signature Domain: Verify that the DKIM signature matches your 'From' domain. Shared sending environments might use the service provider's DKIM.
- Subuser Configurations: SendGrid's subuser settings must be correctly configured, including domain assignments.
- DMARC Policy Review: Review your DMARC policy settings ('reject' or 'quarantine') to ensure they align with your sending practices.
- DMARC Reports Analysis: Enable and analyze DMARC reports to identify the specific causes of DMARC failures.
Key considerations
- Check SPF Alignment: Ensure your SPF record uses your domain, not SendGrid's.
- Verify DKIM Configuration: Make sure the DKIM signature is valid and uses your domain.
- Review DNS Records: Confirm that your DNS records for SPF and DKIM are correctly configured.
- Configure Sendgrid Properly: Properly configure SendGrid, including custom DKIM signatures and Return-Path settings.
- Adjust DMARC Policy: Adjust your DMARC policy and reporting settings according to your organization's needs and monitor for any issues.
- Monitor DMARC Reports: Regularly check DMARC reports to identify and resolve any authentication issues.
Marketer view
Email marketer from Email Geeks shares the solution was that Sendgrid allows subusers, and while domains were authenticated at the root level, they needed to be assigned to the subuser level to be used for sending.
19 Aug 2022 - Email Geeks
Marketer view
Email marketer from MXToolbox.com clarifies that while SPF and DKIM authenticate the source and integrity of the email, DMARC focuses on alignment. Alignment verifies that the domains used in SPF and DKIM match the domain displayed in the 'From' address. When using a third-party sender like Sendgrid, alignment issues are common if not properly configured.
8 Mar 2022 - mxtoolbox.com
What the experts say
6 expert opinions
DMARC failures, despite passing SPF and DKIM in Sendgrid, primarily arise from alignment issues. The 'From' domain must align with the domains used for SPF and DKIM. Using DMARC p=reject necessitates DKIM or SPF with the domain name. Ensure correct public key publication and that the Return-Path isn't Sendgrid's, causing SPF misalignment. Properly align DKIM signatures and SPF records with the 'From' address domain for DMARC compliance.
Key opinions
- Alignment Problems: DMARC requires alignment between the 'From' domain and domains used in SPF and DKIM. Misalignment is a primary cause of DMARC failures.
- DMARC Reject Policy: Using DMARC with a 'reject' policy (p=reject) mandates that either DKIM or SPF authenticates using your domain name.
- Return-Path Issues: A Return-Path header referencing Sendgrid can cause SPF alignment failure. The Return-Path should align with your domain.
- DKIM Signature Validity: Ensure the DKIM signature is valid and signed with your domain. Incorrect or missing DKIM signatures can cause failures.
- SPF Alignment: SPF should be configured to align with your domain, particularly when using a third-party sender like Sendgrid.
Key considerations
- Verify Domain Alignment: Check that your 'From' domain aligns with both SPF and DKIM records.
- Review DNS Records: Examine your DNS records to ensure they are correctly configured for SPF and DKIM to avoid alignment issues.
- Check Public Key Publication: Ensure that you have published the correct public key in your DNS for DKIM verification.
- Configure Sendgrid Return-Path: Configure Sendgrid to use a Return-Path that aligns with your domain, not Sendgrid's.
- Review DMARC Policy: Review your DMARC policy to ensure that it is appropriate for your current email setup. A policy of p=reject requires careful configuration of SPF and DKIM.
Expert view
Expert from Email Geeks explains that to use DMARC p=reject, the mail must have DKIM or SPF with the domain name. The from address domain is agc.org but there is no DKIM or SPF that references agc.org.
8 Feb 2023 - Email Geeks
Expert view
Expert from Email Geeks explains that when agc.org is configured to be DMARC p = reject, it tells ISPs that the d= or SPF has to be in agc.org.
12 Jun 2024 - Email Geeks
What the documentation says
3 technical articles
DMARC failures, despite passing SPF and DKIM in Sendgrid, are primarily caused by alignment issues. DMARC requires the 'From' domain to align with the SPF authenticated domain or the DKIM signing domain. Correctly configuring DNS records for DKIM and SPF is essential, ensuring they are properly implemented and aligned to pass DMARC checks. Without proper alignment, DMARC authentication fails, leading to the enforcement of the specified policy (quarantine or reject).
Key findings
- Alignment Requirement: DMARC mandates that the 'From' domain aligns with the SPF authenticated domain or the DKIM signing domain. Without this alignment, DMARC fails.
- DNS Configuration Importance: Proper configuration of DNS records for both DKIM and SPF is crucial for successful DMARC implementation and alignment.
- DMARC Policy Enforcement: If SPF and DKIM are not aligned with the 'From' domain, DMARC authentication will fail, leading to the application of the specified DMARC policy (quarantine or reject).
Key considerations
- Verify Domain Alignment: Ensure the 'From' domain is aligned with both SPF and DKIM records to meet DMARC requirements.
- Review DNS Configuration: Thoroughly check DNS records for DKIM and SPF to confirm they are correctly set up and without propagation delays.
- Implement Correct Authentication: Ensure that SPF authenticates the sending server and DKIM verifies the message integrity for effective DMARC function.
Technical article
Documentation from DMARC.org defines DMARC alignment as the 'From:' domain aligning with the SPF authenticated domain or the DKIM signing domain. If neither SPF nor DKIM aligns with the 'From:' domain, DMARC authentication will fail, leading to the policy being applied (e.g., quarantine or reject).
24 Aug 2024 - DMARC.org
Technical article
Documentation from Google Workspace Admin outlines that for DMARC to function effectively, both SPF and DKIM must be properly implemented and aligned. SPF authenticates the sending server, while DKIM verifies the message integrity. Alignment ensures that the domains used for SPF and DKIM match the domain in the email's 'From' address. Failure in alignment will cause DMARC to reject or quarantine emails.
13 Aug 2024 - support.google.com
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