Why are spam rates different in Postmaster V1 and V2 for the same domain?
Matthew Whittaker
Co-founder & CTO, Suped
Published 4 Jul 2025
Updated 25 Sep 2025
6 min read
A common source of confusion for email senders is the discrepancy in spam rates between Google Postmaster Tools (GPT) V1 and V2. You might look at your domain and see wildly different figures for the same time period, leading to questions about which data is more accurate or relevant. This difference is not a glitch, but rather a reflection of distinct methodologies used by Google to calculate these crucial metrics.
While both versions aim to help you monitor your sending reputation with Gmail, their approach to defining the recipient base and what constitutes a "spam report" has evolved. Understanding these nuances is key to accurately interpreting your email performance and making informed adjustments to your sending practices. It is about looking beyond the numbers and grasping the underlying data points.
In the following sections, we will explore the core differences in how Postmaster Tools V1 and V2 measure spam rates, the implications of these differences for your deliverability strategy, and how to leverage both tools effectively. Focusing on the more precise metrics of V2 will be crucial as you monitor your email program's health.
The evolving definition of spam rate
The primary reason for differing spam rates between Postmaster Tools V1 and V2 lies in how each version defines the denominator for its calculations. V1 historically calculated spam rates based on "marked as spam over delivered to inbox," meaning anything filtered to spam by Gmail was excluded from the calculation's total email volume. This approach could sometimes paint a more lenient picture.
Postmaster Tools V2, however, refined this calculation by introducing the concept of "engaged users." This means that V2's spam rate specifically considers spam reports against mail delivered to the inboxes of engaged users. The distinction is subtle but profound, as it narrows the focus to recipients who are actively interacting with Gmail.
This shift to engaged users in V2 means that a small number of spam complaints from active recipients can significantly impact your spam rate, even if your overall sending volume to less engaged users is high. The emphasis is on quality engagement, which aligns with modern inbox provider expectations. For a deeper dive into the V2 dashboard, see our article on Understanding Google Postmaster Tools V2 Spam Rate Dashboard.
V1 spam rate calculation
Denominator: Based on all mail delivered to the inbox, excluding mail sent directly to the spam folder.
Reporting scope: Broad assessment of spam reports relative to successful inbox placement.
Latency: Often reports data quicker, sometimes within a day.
V2 spam rate calculation
Denominator: Based on mail delivered to the inbox of engaged users only.
Reporting scope: More precise assessment focusing on active user perception of your mail.
Accuracy: Considered more accurate due to its focus on engagement, providing a clearer picture of user sentiment.
The impact of "engaged users"
Google's inclusion of "engaged users" in the V2 spam rate calculation serves a strategic purpose. It aims to prevent senders from diluting their spam rates by sending to a large volume of inactive or unengaged users, which could mask underlying deliverability issues. If a majority of your emails go to dormant accounts that never report spam, your V1 rate might look artificially low.
With V2, even if you send a large volume of email, a spike in spam complaints from a relatively small segment of active recipients will be more visible. This means that a seemingly low number of actual spam reports can result in a higher percentage in V2, forcing senders to prioritize list hygiene and sending relevant content to engaged subscribers. For insights on managing spam spikes, explore why Google Postmaster Tools spam rates are suddenly spiking.
This refined metric in V2 encourages better sending practices, as a higher reported spam rate can signal to Google that your emails are not desired by its most active users. This can ultimately affect your domain and IP reputation, leading to more emails being routed to the spam folder for all recipients, including engaged ones. It underscores the importance of a clean list and valuable content.
What constitutes an "engaged user"?
Google has not publicly disclosed its exact definition of an "engaged user," but it is generally understood to refer to recipients who regularly interact with Gmail, open emails, mark legitimate emails as "not spam," and move emails out of spam folders. This opaque definition means senders must focus on universal best practices rather than trying to game the system.
Interpreting discrepancies and taking action
Given these differences, it is common to see variations, even "opposite" trends, between V1 and V2 spam rates for the same domain, as observed by many senders. For instance, V1 might show a low spam rate overall, while V2 might show a higher rate for the same period due to complaints from engaged users. This is not necessarily contradictory, but rather two different lenses on your sending performance.
V1 can still offer some utility as an early indicator or a general overview, often reporting data with less latency. However, V2 is generally considered the more accurate and forward-looking metric, especially given Google's continuous efforts to refine its deliverability algorithms to prioritize user experience. Moving forward, V2 will be the definitive measure of your spam rate in Postmaster Tools. You can find more details on Postmaster Tools from Emaillabs about Google Postmaster Tools.
When faced with discrepancies, always prioritize the data from V2, as it reflects Google's current assessment of your emails' reception among its most critical users. Addressing high spam rates in V2 means evaluating your list segmentation, content relevance, and frequency. Regularly monitoring your email deliverability with Suped DMARC monitoring can provide comprehensive insights beyond Postmaster Tools.
Always prioritize list hygiene by regularly removing inactive or unengaged subscribers from your mailing lists.
Segment your audience and tailor your content to ensure relevance for different user groups, reducing spam complaints.
Implement DMARC with a policy of p=quarantine or p=reject to protect your domain from impersonation and improve trust.
Monitor DMARC reports regularly using a tool like Suped to identify authentication issues and potential abuse of your domain.
Encourage explicit opt-ins and use clear unsubscribe options to minimize involuntary spam reports.
Common pitfalls
Relying solely on V1 spam rate, which can underestimate issues by not accounting for engaged user feedback.
Ignoring spikes in V2 spam rates, assuming they are minor because overall volume is high.
Failing to segment lists, leading to irrelevant content for certain user groups and increased spam complaints.
Sending to old, unengaged email lists, which can rapidly increase spam complaint rates.
Not implementing DMARC, leaving your domain vulnerable to spoofing and phishing attacks.
Expert tips
Use V1 as a forward-looking indicator since it sometimes updates faster, but confirm trends with V2 for accurate assessment.
Consider the implications of Google's "engaged user" definition, even if not fully transparent, for your list management strategy.
Analyse campaign-specific data when possible to pinpoint exactly which emails are generating spam complaints in V2.
Look for other email deliverability signals beyond Postmaster Tools, such as open rates, click-through rates, and direct feedback.
Focus on consistent authentication with SPF and DKIM to bolster your domain reputation, which indirectly impacts spam filtering.
Expert view
Expert from Email Geeks says: V2 calculates spam rates based on reports versus mail delivered to the inbox of engaged users, while V1 might use a broader calculation, leading to different results.
2025-09-16 - Email Geeks
Expert view
Expert from Email Geeks says: The difference between V1 and V2 spam rates is likely due to V2 considering only "engaged users," which means the denominator in the calculation is smaller, resulting in potentially higher reported spam rates.
2025-09-17 - Email Geeks
Deliverability beyond the numbers
The differing spam rates between Postmaster Tools V1 and V2 highlight Google's evolving approach to evaluating email sending practices. While V1 offers a general overview, V2's focus on engaged users provides a more precise and actionable metric for understanding your email program's health.
For optimal email deliverability, it is essential to monitor both versions but prioritize insights from V2. Use these metrics to continuously refine your sending strategies, ensuring you target engaged recipients with relevant content. Adopting strong authentication protocols like DMARC and monitoring your reports diligently are also critical steps.
Suped offers powerful DMARC monitoring and reporting tools to help you gain complete visibility into your email authentication, identify threats, and improve your deliverability, helping you navigate these complex reporting landscapes effectively. Start with the most generous free plan available for DMARC reporting.
