Summary
The overwhelming consensus from email marketing experts, documentation from Google, Microsoft, DMARC.org, and RFC, and community discussions is that adding all subdomains used for sending emails to Google Postmaster Tools is essential. This practice ensures a comprehensive view of your email program's reputation by allowing you to track the individual sending health of each subdomain, which maintains its own distinct reputation. This granular monitoring enables proactive identification and resolution of deliverability issues, facilitates separate management of marketing versus transactional emails, and supports proper authentication and reputation management aligned with SPF, DKIM, and DMARC policies.
Key findings
- Complete Reputation View: Adding all subdomains to Google Postmaster Tools provides a comprehensive view of your email program's overall reputation.
- Individual Subdomain Reputation: Each subdomain has a unique sending reputation that is independent of the main domain.
- Early Issue Detection: Monitoring subdomains allows for the early detection and resolution of deliverability issues specific to each subdomain.
- Separate Management: It's best practice to manage marketing and transactional emails using separate subdomains, which each need to be added to Google Postmaster Tools.
- Authentication: Each subdomain needs its own SPF, DKIM and DMARC records.
Key considerations
- Identify All Subdomains: Identify all subdomains used for sending emails, including those used for marketing, transactional, and other purposes.
- Proper Verification: Verify each subdomain within Google Postmaster Tools to ensure accurate tracking and reporting.
- DMARC Implementation: Implement and monitor DMARC policies for each subdomain to ensure proper authentication and reputation management.
- Monitor Regularly: Regularly monitor the sending health of each subdomain in Google Postmaster Tools to proactively address any deliverability issues.
- Use DMARC Data: Use DMARC data to determine if all subdomains are setup correctly.
What email marketers say
12 marketer opinions
The consensus across various email marketing experts and platforms is that it's crucial to add all subdomains to Google Postmaster Tools. Subdomains maintain separate reputations, and monitoring them individually provides a comprehensive view of email performance. This approach enables the early detection and resolution of deliverability issues specific to each subdomain, ensuring optimal email health and reputation.
Key opinions
- Separate Reputations: Subdomains each have individual sending reputations, distinct from the main domain.
- Comprehensive Monitoring: Adding all subdomains enables a complete overview of email performance.
- Early Issue Detection: Monitoring subdomains allows for the early detection and resolution of deliverability issues.
- Authentication Importance: Knowing which subdomains are used for authentication is critical for accurate tracking in Google Postmaster Tools.
Key considerations
- DMARC Data: Utilize DMARC data to identify active subdomains for inclusion in Google Postmaster Tools.
- Authentication Alignment: Ensure proper alignment of SPF and DKIM records for each subdomain to accurately track performance in Google Postmaster Tools.
- Separate Subdomains: Consider using separate subdomains for marketing and transactional emails for better organization and deliverability management.
- Proactive Issue Resolution: Regularly monitor subdomain performance in Google Postmaster Tools to identify and address deliverability issues promptly.
Marketer view
Email marketer from Gmass Blog explains that adding each subdomain allows for tracking of individual sending reputations. As such, each subdomain needs to be added to Google Postmaster Tools in order to spot and resolve domain reputation issues.
2 Dec 2024 - Gmass Blog
Marketer view
Marketer from Email Geeks explains that it's important to know which domains/subdomains are used for authentication. Google Postmaster Tools 'groups' data by either the SPF or DKIM domain. Add all subdomains used for authentication purposes.
18 Jun 2023 - Email Geeks
What the experts say
2 expert opinions
Experts agree that adding all subdomains used for sending emails to Google Postmaster Tools is essential for a complete understanding of your email program's reputation and sending health. This is because each subdomain possesses a unique reputation, making individual monitoring crucial for effectively tracking transactional and marketing emails.
Key opinions
- Complete View: Adding all subdomains provides a complete view of your email program's reputation.
- Unique Reputation: Each subdomain has a unique reputation, requiring individual monitoring.
- Track Separately: Subdomains should be tracked separately, especially for transactional and marketing emails.
Key considerations
- Subdomain Use: Identify all subdomains used for sending emails to ensure comprehensive monitoring.
- Regular Monitoring: Implement a system to regularly monitor the sending health of each subdomain.
- Reputation Tracking: Understand that different types of emails (transactional vs. marketing) might affect the reputation of their respective subdomains.
Expert view
Expert from Spamresource explains that each subdomain has a unique reputation; you should add each one to Google Postmaster Tools to fully monitor and understand its sending health.
1 Jan 2025 - Spamresource
Expert view
Expert from Word to the Wise explains that to get a complete view of your email program's reputation, adding all subdomains used for sending to Google Postmaster Tools is crucial. This allows you to track separate reputations for transactional and marketing emails.
8 Dec 2021 - Word to the Wise
What the documentation says
5 technical articles
Official documentation from Google, Microsoft, RFC, and DMARC.org consistently emphasizes the importance of adding each subdomain to Google Postmaster Tools. This is crucial for granular tracking of reputation metrics, gaining visibility into individual sending reputations, and managing email authentication separately. DMARC policies are applied independently to subdomains, further reinforcing the need for separate monitoring and management.
Key findings
- Granular Tracking: Adding each subdomain allows for granular tracking of reputation metrics.
- Separate Reputations: Subdomains have individual sending reputations that need to be monitored independently.
- Independent DMARC Policies: DMARC policies apply to subdomains independently, requiring separate management.
- Email Authentication: Individual SPF, DKIM and DMARC records for each subdomain.
Key considerations
- Verification: Each subdomain must be verified separately within Google Postmaster Tools.
- SPF Setup: Ensure proper SPF records are set up for each subdomain for email authentication.
- Proactive Monitoring: Regularly monitor each subdomain for deliverability issues and reputation management.
Technical article
Documentation from RFC explains that subdomains are considered to be distinct entities, each capable of having unique SPF, DKIM and DMARC records. Managing email authentication seperately allows you to control each subdomain in Google Postmaster Tools
25 Sep 2022 - RFC-Editor
Technical article
Documentation from DMARC.org states that DMARC policies apply to subdomains independently, meaning each subdomain should be monitored and managed separately in Google Postmaster Tools for proper authentication and reputation management.
8 Mar 2025 - DMARC.org
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