How does Google Postmaster Tools track domain reputation and handle subdomains?

Summary

Google Postmaster Tools (GPT) tracks domain and subdomain reputation based on various factors including spam complaints, feedback loops, email authentication (SPF, DKIM, and DMARC), engagement metrics, and sending volume. GPT tracks reputation individually for each subdomain, making it crucial to monitor them separately, especially for different email types. The 'd=' value in the DKIM signature is a key element in tracking reputation, although Google also tracks the 'from:' line. Proper authentication is vital, as GPT provides insights into issues affecting deliverability. Google may use different thresholds and volume requirements for reputation levels depending on the type of mail. Consistent email volume is also a crucial factor. Registering the main domain in GPT simplifies the addition of subdomains.

Key findings

  • Individual Subdomain Reputation: Google treats each subdomain's reputation independently; poor practices on one subdomain do not impact others.
  • DKIM Signature Importance: GPT tracks reputation primarily through the 'd=' value in the DKIM signature.
  • Comprehensive Authentication Impact: SPF, DKIM, and DMARC authentication methods significantly impact domain reputation with Gmail.
  • Threshold Variance: Google uses different thresholds based on mail verticals/types and volume requirements for specific reputation levels.
  • Volume Matters: Consistent email volume is a crucial factor in establishing and tracking domain reputation.
  • Monitor Metrics: Spam complaints, authentication status, engagement, and traffic patterns all play an important factor in tracking GPT.

Key considerations

  • Separate Setup: Set up each subdomain in GPT to obtain detailed data on its individual performance.
  • Monitor Subdomains Separately: If subdomains handle different types of email, monitor them separately due to potentially varying reputations.
  • Authenticate Domains: Properly implement SPF, DKIM, and DMARC to ensure emails are recognized as legitimate and to improve sender reputation.
  • Understand Volume Thresholds: Consider the email volume requirements for different reputation levels in GPT.
  • Consistent Sending Strategy: Maintain consistent sending volumes to enable accurate reputation scoring by Google.
  • Monitor Metrics: Regularly monitor spam reports, feedback loops, and authentication metrics in Google Postmaster Tools.

What email marketers say
10Marketer opinions

Google Postmaster Tools (GPT) is used to monitor domain and subdomain reputation with Gmail users. GPT tracks reputation individually for each subdomain, making it crucial to monitor each separately, especially if used for different email types. Reputation is based on factors like spam complaints, email authentication (SPF, DKIM, DMARC), engagement metrics, and sending volume. Registering the main domain in GPT facilitates adding subdomains. Monitoring sender reputation is essential for identifying and addressing issues affecting email deliverability.

Key opinions

  • Individual Subdomain Reputation: Google treats each subdomain's reputation independently. Poor practices on one subdomain do not necessarily impact others.
  • Granular Monitoring: GPT enables monitoring of individual subdomains, allowing for granular insights into performance.
  • Key Metrics: GPT tracks reputation based on spam complaints, authentication status, engagement, and sending volume.
  • Email Authentication is Key: Email authentication is extremely important, and that Google will track unauthenticated mail.

Key considerations

  • Separate Setup: Set up each subdomain in GPT to obtain detailed data on its individual performance.
  • Differentiated Email Streams: If subdomains handle different types of email (e.g., marketing vs. transactional), monitor them separately due to potentially varying reputations.
  • Proactive Monitoring: Regularly monitor sender reputation in GPT to identify and address issues affecting deliverability promptly.
  • Authentication methods: Domain reputation is a key factor, so be sure to implement SPF, DKIM, and DMARC.
Marketer view

Email marketer from Gmass explains the importance of email authentication, and that Google will track unauthenticated mail and that it is a key factor in tracking domain reputation.

July 2021 - Gmass
Marketer view

Email marketer from SparkPost Blog responds by sharing that while Google Postmaster Tools provides overall domain reputation, it's crucial to monitor subdomains separately if they handle distinct email streams. Different subdomains might have varying sender reputations based on their sending practices.

November 2022 - SparkPost Blog

What the experts say
4Expert opinions

Google Postmaster Tools tracks domain reputation primarily through the 'd=' value in the DKIM signature, irrespective of the sending domain or IP. Adding authenticated subdomains is automated in GPT. Google uses different thresholds based on mail verticals and requires specific volumes to assess reputation levels. Email volume is a vital factor for establishing and monitoring domain reputation, allowing Google to accurately gauge sender behavior and assign scores.

Key opinions

  • DKIM Signature Tracking: GPT primarily tracks domain reputation through the 'd=' value in the DKIM signature.
  • Automated Subdomain Addition: Adding authenticated subdomains to GPT is an automated process.
  • Variable Thresholds: Google uses different thresholds for reputation assessment based on mail verticals and types.
  • Volume Importance: Consistent email volume is critical for establishing and accurately tracking domain reputation.

Key considerations

  • DKIM Alignment: Ensure proper DKIM configuration to align with domain reputation tracking in GPT.
  • Domain Authentication: Authenticate subdomains to enable automatic addition to GPT.
  • Volume Thresholds: Understand the email volume requirements for different reputation levels in GPT.
  • Consistent Sending: Maintain consistent sending volumes to enable accurate reputation scoring by Google.
Expert view

Expert from Spam Resource explains that email volume is a crucial factor in establishing and tracking domain reputation in Google Postmaster Tools. Consistent sending volumes enable Google to accurately assess sender behavior and assign reputation scores.

March 2024 - Spam Resource
Expert view

Expert from Email Geeks explains that Google Postmaster Tools defaults to tracking by the d= value in the DKIM signature and it has nothing to do with the sending domain or sending IP. Google will track each domain reputation in the from: line as well, but you just don’t get that data.

July 2023 - Email Geeks

What the documentation says
4Technical articles

Google Postmaster Tools provides insights into domain reputation using metrics like spam reports, feedback loops, and authentication results to identify deliverability issues. SPF, DKIM, and DMARC authentication methods significantly impact domain reputation by ensuring emails are recognized as legitimate. The 'd=' tag in the DKIM signature associates emails with a domain, which GPT uses for tracking. DMARC policy allows domain owners to specify how to handle unauthenticated email, affecting the domain's reputation tracked by Google Postmaster Tools.

Key findings

  • Comprehensive Insights: Google Postmaster Tools offers insights into domain reputation through spam reports, feedback loops, and authentication metrics.
  • Authentication Impact: SPF, DKIM, and DMARC authentication methods directly affect domain reputation with Gmail.
  • DKIM Signature: The 'd=' tag in the DKIM signature is used by Google Postmaster Tools to track domain reputation.
  • DMARC Policy Influence: DMARC policy influences domain reputation by specifying how unauthenticated emails should be handled.

Key considerations

  • Monitor Metrics: Regularly monitor spam reports, feedback loops, and authentication metrics in Google Postmaster Tools.
  • Implement Authentication: Properly implement SPF, DKIM, and DMARC to ensure emails are recognized as legitimate and improve sender reputation.
  • DKIM Configuration: Ensure correct configuration of the DKIM signature to align with domain reputation tracking.
  • DMARC Policy: Establish and maintain a clear DMARC policy to specify how unauthenticated emails should be handled.
Technical article

Documentation from RFC 4871 answers how DKIM signatures associate an email with a specific domain. The 'd=' tag in the DKIM signature indicates the domain responsible for the email, which Google Postmaster Tools uses for tracking domain reputation.

February 2024 - RFC 4871
Technical article

Documentation from Google Postmaster Tools Help explains that the tool provides insights into your domain's reputation with Gmail users, including spam reports, feedback loop, and authentication metrics. It helps you identify potential issues affecting your email deliverability.

March 2023 - Google Postmaster Tools Help