Why is my primary domain not compliant with Google one-click unsubscribe while the subdomain is?

Summary

The primary domain's failure to comply with Google's one-click unsubscribe requirements, while the subdomain passes, results from a confluence of factors. These span technical configurations, reputation considerations, and content-related elements. Key technical aspects involve missing or improperly formatted List-Unsubscribe headers, DNS misconfigurations (SPF, DKIM, DMARC), and incorrect rDNS records. Reputation issues arise from spoofing, historical baggage affecting the primary domain, presence on blocklists, and different engagement patterns. Content-related factors include inconsistencies in branding, URL shortener usage, and email content differences that trigger spam filters. The consensus emphasizes a thorough audit and consistent implementation of best practices across both domains.

Key findings

  • Unsubscribe Header Issues: Missing or incorrectly formatted `List-Unsubscribe` and `List-Unsubscribe-Post` headers in the primary domain.
  • DNS Misconfigurations: Inconsistent or incorrect SPF, DKIM, and DMARC configurations between the primary domain and subdomain.
  • Reputation Damage: Poor sender reputation of the primary domain due to spam complaints, low engagement, or blocklisting.
  • Spoofing and Forged Mail: Primary domain potentially targeted by spoofing or forged mail, leading to compliance flags.
  • Historical Baggage: The primary domain may be impacted by past sending practices, even if currently inactive.
  • Content Inconsistencies: Differences in email content, branding, and sender information between the primary and subdomain.
  • Google Scrutiny: Google may apply more rigorous checks to root domains compared to subdomains.
  • rDNS Misconfiguration: Improperly configured reverse DNS (rDNS) records impacting deliverability.

Key considerations

  • Implement and Monitor DMARC: Set up DMARC to monitor mail sources, prevent spoofing, and identify authentication issues.
  • Audit and Align DNS: Thoroughly audit and align SPF, DKIM, and DMARC records for both the primary domain and subdomain.
  • Monitor Reputation: Regularly monitor sender reputation using tools and promptly address any issues (e.g., blocklist removal).
  • Review Unsubscribe Headers: Verify the presence and correct formatting of List-Unsubscribe headers, including both mailto: and https: options.
  • Ensure Consistent Branding: Maintain consistent branding and sender information across all email communications.
  • Analyze Sending Practices: Review sending practices and content for the primary domain to avoid spam triggers.
  • Verify rDNS: Ensure reverse DNS records are correctly configured to point from IP addresses to domain names.
  • Address Caching: Consider DNS caching issues and advise recipients to flush their DNS if needed.

What email marketers say
12Marketer opinions

The primary domain may fail Google's one-click unsubscribe compliance while the subdomain passes due to a combination of factors. These include misconfigured DNS records (SPF, DKIM, DMARC), poor sender reputation stemming from spam complaints or low engagement, recent addition to blocklists, cached DNS records, discrepancies in IP addresses (including usage of blacklisted IPs), more rigorous checks on root domains by Google, differing sending volumes and engagement patterns, inconsistent branding/sender information, use of URL shorteners, differing email content triggering compliance filters, and different feedback loop results. In essence, the primary domain might be subject to more scrutiny or historical issues not present in the subdomain.

Key opinions

  • DNS Configuration: Inconsistent or incorrect SPF, DKIM, and DMARC configurations between the primary domain and subdomain can lead to compliance issues.
  • Sender Reputation: The primary domain might have a poor sender reputation due to past spam complaints, low engagement, or presence on blocklists.
  • Caching Issues: Cached DNS records, either on the sender's or recipient's side, may prevent the most recent DNS settings from being applied.
  • IP Address Discrepancies: The primary domain and subdomain could be using different IP addresses, and the primary domain's IP might be blacklisted.
  • Content and Branding Inconsistencies: Differences in email content, branding, and sender information between the primary and subdomain can trigger compliance filters.
  • Domain Scrutiny: Google may subject root domains to more rigorous compliance checks than subdomains.
  • Feedback Loop Differences: Different feedback loop (FBL) results between primary and subdomains can cause compliance differences.

Key considerations

  • Audit DNS Records: Thoroughly audit and align SPF, DKIM, and DMARC records for both the primary domain and subdomain.
  • Monitor Sender Reputation: Check the sender reputation of the primary domain using reputation monitoring tools and address any issues.
  • Flush DNS Cache: Flush DNS caches and encourage recipients to do the same to ensure the latest settings are applied.
  • Check IP Addresses: Verify the IP addresses used by both domains and ensure they are not blacklisted. Use reputable IP addresses.
  • Ensure Consistent Branding: Maintain consistent branding and sender information across all email communications from both domains.
  • Review Email Content: Review email content from the primary domain to ensure it complies with Google's policies and avoid potential spam triggers.
  • Monitor Feedback Loops: Monitor and respond to feedback loop (FBL) data for both domains and address any negative feedback.
Marketer view

Marketer from Email Geeks agrees with Al Iverson, and states that DMARC reports are the first thing to reach for, as there is often a "surprise" system found that only a few people in the company know about. Culprits often involve dev, support and SDRs.

January 2022 - Email Geeks
Marketer view

Email marketer from emailgeeks.com states that the issue could be due to inconsistent configurations across your primary domain and subdomain. Ensure your DNS records (SPF, DKIM, DMARC) are properly configured and aligned for both. If the primary domain's records are misconfigured or missing, Google might flag it as non-compliant.

September 2024 - emailgeeks.com

What the experts say
3Expert opinions

The primary domain's non-compliance with Google's one-click unsubscribe, while the subdomain is compliant, may be attributed to factors like forged mail or spoofing, differing reputation handling with historical baggage affecting the primary domain, and variations in DKIM or SPF records causing authentication issues. Setting up and correctly interpreting DMARC records is crucial to identifying and rectifying these issues.

Key opinions

  • Forged Mail/Spoofing: The primary domain might be seen as non-compliant due to forged mail or corporate 1:1 mail being spoofed, leading Google to flag it.
  • Reputation Differences: Subdomains may inherit a 'clean slate' reputation more easily than the primary domain, which carries historical sending baggage that can affect compliance.
  • Authentication Issues: Different DKIM or SPF records on the primary domain compared to the subdomain can result in authentication failures, affecting compliance.

Key considerations

  • Implement DMARC: Set up DMARC to gain visibility into mail sources and identify potential spoofing or unauthorized sending.
  • Audit Historical Practices: Consider the past sending practices of the primary domain and how they might be affecting its current reputation.
  • Audit DNS Records: Conduct a thorough audit of DKIM, SPF, and DMARC records to ensure proper configuration and alignment across both domains.
  • Interpret DMARC Reports: Ensure you are actively interpreting DMARC reports to identify issues relating to Google's one-click unsubscribe compliance.
Expert view

Expert from Email Geeks suggests that the primary domain's uncompliance could be due to forged mail or corporate 1:1 mail being spoofed by someone else. Al also suggests setting up DMARC to gain visibility into mail sources.

January 2023 - Email Geeks
Expert view

Expert from Word to the Wise (Laura Atkins) responds that the primary domain may have different DKIM or SPF records, leading to authentication issues. A thorough audit of DNS records is crucial to ensure both domains are properly configured. It is critical to ensure that DMARC is set up and interpreted correctly to help identify issues relating to Google's one-click unsubscribe compliance.

January 2024 - Word to the Wise

What the documentation says
4Technical articles

The primary domain may be non-compliant with Google's one-click unsubscribe requirements due to missing or improperly formatted `List-Unsubscribe-Post` or `List-Unsubscribe` headers. The `List-Unsubscribe` header requires both `mailto:` and `https:` options. Internal communications on the primary domain might lack proper authentication (DMARC, SPF, DKIM). Also, misconfigured reverse DNS (rDNS) records, even if the domain isn't actively sending, can impact deliverability.

Key findings

  • Missing/Incorrect Headers: Absence or incorrect formatting of `List-Unsubscribe-Post` and `List-Unsubscribe` headers are likely causes.
  • Header Requirements: `List-Unsubscribe` header must include both `mailto:` and `https:` options for compliance.
  • Authentication Issues: Internal communications on the primary domain may lack proper DMARC, SPF, and DKIM authentication.
  • rDNS Configuration: Misconfigured reverse DNS (rDNS) records can impact deliverability, even if the domain isn't actively used for sending.

Key considerations

  • Check Unsubscribe Headers: Verify the presence and correct formatting of `List-Unsubscribe-Post` and `List-Unsubscribe` headers on the primary domain.
  • Implement Both Options: Ensure the `List-Unsubscribe` header includes both `mailto:` and `https:` options.
  • Configure Authentication: Properly configure DMARC, SPF, and DKIM for the primary domain, even if used primarily for internal communications.
  • Verify rDNS Records: Ensure that reverse DNS (rDNS) records correctly point from your IP addresses to your domain names for both the primary domain and subdomain.
Technical article

Documentation from SparkPost shares that even if the email isn't being sent from the main domain, misconfigured reverse DNS (rDNS) records can impact deliverability. Ensure that rDNS records correctly point from your IP addresses to your domain names for both the primary domain and subdomain.

November 2021 - SparkPost
Technical article

Documentation from RFC-Editor.org explains that the List-Unsubscribe header must be properly formatted and include both a mailto: and an https: option. A non-compliant domain might only have one or neither, while the compliant subdomain includes both and they are correctly formatted.

May 2023 - RFC-Editor.org