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

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.

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.

Email marketer from Reddit explains that Google might be caching old DNS records for your primary domain. Flush your DNS cache and also request your recipients to flush their DNS cache, to make sure the latest settings are being used.

Email marketer from Email on Acid emphasizes the importance of consistent branding and sender information. Discrepancies between the branding in your email content and the information associated with your primary domain might be triggering compliance warnings. Ensure that your branding and sender information is uniform across all sending domains.

Email marketer from Sender.net indicates a discrepancy in the IP addresses used to send emails from the primary domain and subdomain. Even if the domain name looks correct, using a blacklisted IP address for the primary domain can cause issues.

Email marketer from Sendgrid suggests that different feedback loop (FBL) results between the primary and subdomains can cause compliance differences. Ensure you're monitoring and responding to FBL data for both domains.

Email marketer from GMass states that Google might perform more rigorous checks on root domains vs. subdomains for various compliance factors. Ensure that all aspects of your sending setup, including infrastructure, content, and sending practices, are fully compliant.

Email marketer from StackOverflow shares that the primary domain could be failing because it's recently been added to blocklists. Check if the primary domain is listed on any DNSBLs (DNS Blocklists) and take steps to get it removed if necessary.

Email marketer from Mailchimp Support suggests that differences in email content might trigger different compliance filters. Review the content sent from your primary domain for anything that could be flagged as spam or violating Google's policies.

Email marketer from MailerQ states that using URL shorteners in emails sent from the primary domain, while not used in the subdomain, might cause the primary domain to be flagged. Some URL shorteners are associated with spam or phishing attempts.

Email marketer from Litmus explains that your primary domain might have a different sending volume and engagement pattern than your subdomain. Low engagement or high bounce rates from your primary domain could result in Google being more stringent.

Email marketer from Mailfence support suggests that the primary domain might have a poor sender reputation due to spam complaints or low engagement, even if it's not actively used. Google may treat the primary domain more cautiously. Check sender reputation tools to identify any issues.

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.

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.

Expert from SpamResource explains that the issue may stem from differing handling of reputation data. Subdomains may inherit a 'clean slate' reputation more easily than the primary domain, which carries historical baggage. The primary domain's prior sending practices, even if currently inactive, could still affect its compliance rating.

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.

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.

Documentation from Microsoft Learn explains that if the primary domain is used for internal communications, it might not have proper authentication configured, as internal emails often bypass strict checks. Ensure both domains have DMARC, SPF, and DKIM configured.

Documentation from Google Workspace Updates explains that one reason for non-compliance could be the absence of the List-Unsubscribe-Post header or incorrect formatting of the List-Unsubscribe header. The primary domain might be missing these headers or have them configured incorrectly, while the subdomain has them properly set up.