Why is Gmail deliverability down despite good reputation?
Matthew Whittaker
Co-founder & CTO, Suped
Published 24 Jul 2025
Updated 15 Aug 2025
6 min read
Many senders experience a perplexing issue: their Gmail deliverability drops significantly, even when Google Postmaster Tools reports a high reputation. This can be incredibly frustrating, leaving you wondering why your emails are no longer reaching the inbox.
We often rely heavily on metrics provided by Postmaster Tools, which might show high IP and domain reputation, yet our open rates plummet. This disconnect indicates that other, less obvious factors are influencing how Gmail perceives your sending practices.
It is crucial to look beyond the surface metrics and investigate the deeper nuances of Gmail's filtering algorithms. Understanding these intricate elements is key to diagnosing and resolving unexpected deliverability dips.
Beyond Google Postmaster Tools reputation
While Postmaster Tools offers valuable insights into your sending domain and IP reputation, it doesn't always tell the whole story. A 'high' reputation in Postmaster Tools reflects a general trustworthiness, but Gmail's filtering decisions are also influenced by more granular, real-time engagement signals.
For instance, if your spam rate shows 0.0% but your open rates have halved, it could mean a large portion of your emails are going straight to the spam folder, never to be opened. This scenario results in an artificially low spam complaint rate in Postmaster Tools because unengaged recipients simply aren't seeing your messages to mark them as spam.
It is important to remember that Postmaster Tools is one of many signals Google uses. Factors outside of its reported reputation metrics can significantly impact inbox placement, including specific content issues or sudden changes in sending behavior. For more detail on this, check out this guide on Postmaster Tools.
Understanding your data
Google Postmaster Tools provides reputation data, but a high score doesn't guarantee inbox placement. It's a key indicator, but not the only one.
A spam rate of 0.0% might seem ideal, but if combined with low open rates, it could signal that emails are being filtered to spam before users have a chance to engage or report them.
Always cross-reference Postmaster Tools data with your own campaign metrics to get a comprehensive view of your Gmail deliverability.
The critical role of user engagement
Gmail prioritizes user experience above all else. This means that recipient engagement is a primary driver of your inbox placement. Even with a stellar reputation, if your subscribers aren't opening, clicking, or replying to your emails, Gmail's algorithms will interpret this as a lack of interest, potentially pushing your messages to the spam folder.
Low engagement signals to Gmail that your emails might not be wanted, even if they aren't explicitly marked as spam. This silent filtering can lead to a significant drop in visible open rates and conversions, without a corresponding increase in complaint rates reported by Google Postmaster Tools.
Conversely, positive engagement, such as frequent opens, clicks, and replies, reinforces your sender reputation and signals to Gmail that your emails are valued. Encouraging meaningful interaction with your content is paramount for sustained inbox delivery. This helps Gmail determine whether your emails should land in the primary inbox or elsewhere. You can learn more about how user engagement affects deliverability.
Factor
Impact on deliverability
Opens
Increased opens signal relevance, improving inbox placement.
Clicks
High click-through rates demonstrate interest, boosting sender score.
Replies
Direct replies are strong positive signals, enhancing reputation.
Beyond reputation and engagement, the content of your emails and certain technical configurations play a significant role. Even if your domain has a high standing, specific elements within your message can trigger spam filters. This includes overly promotional language, suspicious links, or an imbalanced image-to-text ratio.
Ensure your email content is clean, relevant, and free from characteristics commonly associated with spam. This might mean reviewing recent campaign changes, especially any new links or calls to action that could be raising red flags. A single problematic link could indeed be the cause of a sudden dip in deliverability. You can refer to this guide on avoiding the Gmail spam filter.
Proper email authentication, including SPF, DKIM, and DMARC, is fundamental. While often set up correctly, misconfigurations or recent changes could inadvertently affect your deliverability. Ensure your DMARC records are correctly configured and monitored, as this provides crucial feedback on your email streams. You can refer to our article on a simple guide to DMARC, SPF, and DKIM for more information.
An often-overlooked aspect of maintaining Gmail deliverability, despite a good reputation, is the health of your email list. Sending to outdated, unengaged, or purchased lists can lead to increased bounces and spam complaints, even if those aren't immediately reflected as a lowered reputation in Postmaster Tools. This behavior can cause a sudden drop in Gmail email deliverability to spam.
Spam traps are another serious threat. These are dormant email addresses used by ISPs to identify senders with poor list hygiene. Hitting a spam trap, even once, can severely damage your sender reputation and lead to immediate blocklisting (or blacklisting), regardless of your perceived "good" reputation. Regularly cleaning your list is essential to avoid these pitfalls, and it's a key part of fixing email deliverability.
Implementing a consistent sending volume and segmenting your audience are also best practices. Irregular sending patterns or large, sudden spikes in volume can trigger Gmail's spam filters, which look for unusual behavior. Tailoring content to specific, engaged segments improves relevance and, consequently, engagement metrics, which further bolsters your sender reputation. Maintaining a constant volume of emails helps keep your sender reputation stable.
Healthy list practices
Regularly verify email addresses to reduce bounce rates.
Remove inactive subscribers who haven't engaged in a long time.
Use double opt-in to ensure subscribers genuinely want your emails.
Proactive cleaning: Continuously cleanse your email list to remove invalid or dormant addresses.
Engagement segmentation: Target engaged users with specific content to maintain high interaction rates.
Unhealthy list practices
Sending to purchased or rented lists.
Neglecting to remove hard bounces or unengaged contacts.
Not using a clear unsubscribe process.
Spam traps: Risk hitting spam traps, which can lead to immediate blacklisting and severe reputation damage.
Low engagement: Contributes to low open and click rates, signaling to ISPs that your emails are not valuable.
Views from the trenches
Best practices
Continuously monitor a variety of email deliverability metrics beyond just reputation scores.
Prioritize user engagement as a key indicator of email relevance and sender trustworthiness.
Regularly clean and segment your email lists to maintain high quality and avoid spam traps.
Ensure all email authentication protocols are correctly configured and regularly audited.
Maintain consistent sending volumes and avoid sudden, unannounced spikes in email campaigns.
Common pitfalls
Solely relying on Google Postmaster Tools for a complete picture of deliverability health.
Ignoring low open or click rates, mistaking them for general audience fatigue rather than deliverability issues.
Sending to outdated or unverified email lists, which can lead to spam trap hits.
Making significant changes to email content, such as links or calls to action, without testing their impact.
Inconsistent sending volumes that can trigger automated spam filters and reputation penalties.
Expert tips
Cross-reference Postmaster Tools data with your own internal campaign analytics for a holistic view.
Consider A/B testing email content and subject lines to optimize for engagement and avoid spam triggers.
Look for subtle changes in recipient behavior, such as deletes without opening, which indicate a lack of interest.
Investigate if any new links or content in recent emails might be negatively impacting Gmail's perception.
If open rates drop but Postmaster Tools shows 0.0% spam, it often means emails are going straight to spam folders.
Marketer view
Marketer from Email Geeks says mail will go to spam even with a high reputation if there is something else in the email that is bad enough. A single day of data is not enough, as it might be a one-off issue or the start of a trend.
2020-04-10 - Email Geeks
Marketer view
Marketer from Email Geeks says even with high IP and domain reputations in Postmaster Tools, their Gmail open rates suddenly dropped by half after launching a sale, indicating a possible spam folder issue.
2020-04-10 - Email Geeks
Navigating Gmail's evolving landscape
Recovering from a dip in Gmail deliverability, even with a seemingly good reputation, requires a multi-faceted approach. It involves digging deeper into engagement metrics, scrutinizing content, reinforcing technical setup, and meticulously managing your subscriber list.
The path to consistent inbox placement lies in understanding that Gmail's algorithms are dynamic and constantly learning from user interactions. By focusing on providing valuable content to an engaged audience and maintaining strong technical foundations, you can improve your deliverability and ensure your messages consistently reach their intended destination.
Google uses. Factors outside of its reported reputation metrics can significantly impact inbox placement, including specific content issues or sudden changes in sending behavior. For more detail on this, check out this guide on Postmaster Tools.
Gmail deliverability.
