Is DKIM domain alignment required for Google and Yahoo's new email sending requirements?

Key findings

• No strict requirement: There is no explicit requirement from Google or Yahoo for tracking links or List-Unsubscribe headers to align with the DKIM signing domain.
• List-Unsubscribe signing: The List-Unsubscribe header must be signed by DKIM, but its domain does not need to align with the d= domain in the DKIM signature itself. More details on how DKIM and List-Unsubscribe domains align are available.
• DMARC alignment: For bulk senders, DMARC authentication is crucial, which relies on either SPF or DKIM alignment with the From: domain.
• General authentication: All senders must implement SPF or DKIM, and bulk senders must also implement DMARC.

Key considerations

• Reputation benefits: While not strictly required, aligning all domains (including tracking and unsubscribe) with your primary sending domain can enhance your overall sending reputation.
• Consistency matters: Maintaining consistency across your email infrastructure reduces complexity and potential issues.
• Shared domains: If using a shared domain, consider how new policies affect shared domains and ESP authentication.
• DMARC policy impact: A robust DMARC policy with proper SPF and DKIM alignment for your From: domain is the primary focus of the new requirements. Learn more about new email requirements.

Key opinions

• Unsubscribe link alignment: Many marketers initially thought the List-Unsubscribe domain needed to strictly align with the DKIM signing domain, but this is not the case.
• General alignment benefits: Despite no strict requirement, aligning all relevant domains is seen as a good practice to improve overall sender reputation and trustworthiness.
• DMARC is key: The primary focus for compliance is ensuring proper DMARC implementation and alignment with the From: header.
• SPF and DKIM foundations: Marketers emphasize the foundational need for correctly configured SPF and DKIM records for all sending domains.

Key considerations

• Understanding specific rules: Marketers need to differentiate between general best practices and the specific, mandatory requirements from Gmail and Yahoo.
• Impact on deliverability: Even if not strictly required, misalignment in other areas could still impact email deliverability, pushing emails to spam. Review our guide on why emails go to spam.
• Communication with ESPs: Senders should consult with their email service providers (ESPs) to ensure their platform's configurations meet the new alignment standards.
• Holistic view: It is advisable to view domain alignment as part of a holistic email deliverability strategy rather than isolated requirements. See Twilio's insights on new requirements.

Key opinions

• No universal alignment: Experts confirm that there's no blanket requirement for all email components, like tracking links, to fully align with the DKIM signing domain.
• List-Unsubscribe specific: The List-Unsubscribe header must be DKIM signed, but its domain is not required to align with the d= domain.
• DMARC enforcement: The main focus remains on proper DMARC implementation, which requires either SPF or DKIM to align with the From: domain. More on understanding DMARC, SPF, and DKIM.
• Beyond the minimum: While not mandated, aligning additional domains can be a strategic move to build stronger sender reputation and mitigate risks associated with shared domains.

Key considerations

• Prioritize core authentication: Experts advise ensuring SPF, DKIM, and DMARC are correctly set up and aligned before worrying about non-mandated alignments. For specific DMARC/DKIM/SPF updates, consult relevant guides.
• Avoid over-engineering: Adding unnecessary alignment configurations can complicate setup without providing significant deliverability gains beyond the core requirements.
• Stay informed: Keep abreast of official announcements and reputable industry sources for any evolving requirements or clarifications. Access FAQs from Word to the Wise.
• Reputation building: Focus on consistent sending practices, low complaint rates, and a strong domain reputation, which are more impactful than niche alignment details.

Key findings

• From header alignment: The primary alignment requirement is that the domain in the From: header must align with either the SPF or DKIM domain for DMARC to pass.
• Authentication standards: All senders must authenticate emails with SPF or DKIM. Bulk senders also need a valid DMARC policy.
• No explicit tracking link rule: Documentation does not explicitly state a requirement for tracking link domains to align with the DKIM signing domain.
• List-Unsubscribe signing: The List-Unsubscribe header must be signed by DKIM, but its domain doesn't need to match the d= domain.

Key considerations

• Review official guidelines: Always refer to the official Google and Yahoo sender guidelines for the most accurate and up-to-date information. They are the definitive source.
• Focus on DMARC: For senders, particularly bulk senders, compliance with DMARC's alignment requirements is paramount. Learn how to safely transition DMARC policies.
• Technical setup: Ensure your DNS records for SPF, DKIM, and DMARC are correctly published and maintained to meet technical requirements.
• Forward and reverse DNS: Sending domains or IPs must have valid forward and reverse DNS records (PTR), which contributes to sender legitimacy. Mimecast details Google and Yahoo changes.