Why are my emails struggling with Gmail open rates and inbox placement?
Michael Ko
Co-founder & CEO, Suped
Published 2 Oct 2025
Updated 2 Oct 2025
6 min read
Many email marketers and senders are noticing deflated open rates and a harder time getting emails into the Gmail inbox, based on seed testing and other metrics. This isn't an isolated issue, but rather a reflection of Gmail's continuously evolving algorithms and stricter filtering practices. If your emails are struggling to reach recipients, or if your engagement metrics are declining specifically with Gmail users, it’s crucial to understand the underlying causes and implement effective solutions.
The challenge often stems from a combination of technical factors, content quality, and user engagement signals that Gmail heavily weighs. Addressing these issues requires a systematic approach, from ensuring robust email authentication to optimizing your email content and managing your sender reputation diligently. Ignoring these aspects can lead to emails consistently landing in spam or the less-visible Promotions tab, ultimately impacting your overall email marketing effectiveness.
We will explore the key reasons behind low Gmail open rates and poor inbox placement, and provide actionable strategies to help you navigate Gmail's complex filtering system.
Understanding Gmail's filtering logic
Gmail’s primary goal is to protect its users from unwanted mail, which means its filtering algorithms are sophisticated and constantly updated. These algorithms analyze numerous factors to determine if an email belongs in the primary inbox, the Promotions tab, or the spam folder. One of the biggest shifts has been the increased emphasis on user engagement signals.
If recipients frequently open, reply to, or move your emails out of spam, Gmail learns that your messages are valuable. Conversely, if they ignore, delete without opening, or mark your emails as spam, your sender reputation suffers, making it harder to reach the inbox. This personal history of engagement significantly influences how future emails from your domain are handled for individual users, as well as influencing your overall domain reputation.
Gmail's evolving filtering
Gmail's filtering has become more dynamic. Senders who were historically fine with their content are now finding their emails squeezed out due to factors like oversized images, bloated HTML, or a high number of different domains involved in the email content. Gmail-specific best practices are more critical than ever.
The Promotions tab is another significant factor. While not the spam folder, emails landing there often see a considerable drop in open rates simply because users check it less frequently. Understanding why your information emails land in the Promotions tab is key to optimizing your campaigns for better primary inbox placement.
Ensuring strong technical authentication
Robust email authentication is the bedrock of good deliverability. Gmail rigorously checks for SPF, DKIM, and DMARC records to verify that your emails are legitimate and haven't been tampered with. Missing or misconfigured records can immediately flag your emails as suspicious, sending them straight to spam.
Protocol
Purpose
Impact on deliverability
SPF
Authorizes specific IP addresses to send email on behalf of your domain.
Helps prevent spoofing and ensures mail originates from approved servers.
DKIM
Digitally signs outgoing emails to verify content integrity and sender identity.
Ensures email content hasn't been altered in transit, building trust.
DMARC
Aligns SPF and DKIM, telling receiving servers how to handle emails that fail authentication.
Provides reporting and policy enforcement, crucial for preventing phishing and spoofing. Suped provides leading DMARC monitoring.
Your sender reputation, tied to your domain and IP address, also plays a critical role. A poor reputation can lead to emails being blocklisted (or blacklisted), which means they'll likely be rejected or sent to spam by major mailbox providers, including Gmail. Regularly understanding your email domain reputation and checking for blocklist placements is essential for maintaining deliverability.
Using a robust DMARC monitoring tool, like Suped, provides visibility into your email authentication status and helps you quickly identify and resolve issues that could be hurting your inbox placement.
Content, list hygiene, and engagement strategies
Beyond technical setup, the actual content of your emails and how your subscribers interact with them are critical. Gmail's filters analyze factors like email size, HTML complexity, and the number of linked domains. Oversized images, excessively large HTML, or a multitude of external links can trigger filters. Simplifying your templates and ensuring a clean code base is often a good starting point.
Content pitfalls
Heavy HTML: Emails with excessive code or large file sizes can be deprioritized by Gmail.
Oversized images: Large images can increase email load times and signal lower quality to filters.
Too many domains: Involving numerous different domains within your content can raise spam flags.
Irrelevant content: Lack of personalization or sending to uninterested subscribers leads to poor engagement.
List hygiene is another critical area. Sending emails to inactive, invalid, or fake addresses can significantly harm your sender reputation, increasing bounce rates and spam complaints. Regularly cleaning your email list to remove unengaged subscribers and invalid addresses is paramount. This can prevent you from hitting spam traps, which are designed to catch senders with poor list management practices.
Finally, the relevance of your emails matters more than ever. If your content doesn't resonate with your audience, they won't open, click, or engage. This tells Gmail that your emails are not valuable, leading to lower inbox placement. Continuous A/B testing of creatives, subject lines, and content can help you find what works best for your audience and maintain equilibrium with Gmail's filters.
Monitoring and continuous improvement
Proactive monitoring is non-negotiable for maintaining good Gmail deliverability. Tools like Google Postmaster Tools provide invaluable insights into your domain and IP reputation, spam rates, feedback loops, and authentication errors directly from Google. Regularly checking these dashboards can help you spot issues before they severely impact your deliverability.
DMARC reports offer another layer of crucial visibility, showing you which of your emails are passing or failing authentication, and from which sending sources. Analyzing these reports is vital for identifying unauthorized sending or misconfigurations that could be hurting your sender reputation. Suped provides the most generous free DMARC monitoring plan, offering accessible tools to help you track your authentication status effectively.
Email deliverability is not a set-it-and-forget-it task. Gmail’s algorithms, user behaviors, and the email landscape itself are constantly changing. Continuous optimization, including regular troubleshooting for sudden drops in open rates, is essential. Stay informed about industry best practices and keep adapting your email program to maintain optimal inbox placement and engagement.
Views from the trenches
Best practices
Actively simplify email templates and HTML to reduce overall message size.
Consolidate external domains used within email content to avoid triggering filters.
Prioritize contact targeting to ensure emails are relevant to the audience.
Implement a robust A/B testing strategy for creatives and subject lines.
Regularly monitor
Common pitfalls
Using oversized images or bloated HTML that increases email load times.
Involving too many different domains within the email content itself.
Neglecting list hygiene, leading to sending to unengaged or invalid addresses.
Failing to personalize content, resulting in low user engagement.
Assuming past deliverability success guarantees future inbox placement.
Expert tips
Focus on content relevance above all else; it is the ultimate determinant for Gmail.
Understand that Gmail's filters learn individual user engagement histories.
Brand senders often have better success than affiliate marketers due to stricter filtering.
Adjusting templates and running them through simplification tools can yield positive results.
Continuously adapt your email strategy as Gmail's algorithms evolve.
Expert view
Expert from Email Geeks says that many senders who were historically fine are now experiencing issues due to oversized images, bloated HTML, or a high number of different domains involved in the content.
2025-09-24 - Email Geeks
Marketer view
Marketer from Email Geeks says that they are working on template fixes and running them through AI tools to simplify them, which is showing some success, but they still struggle to stay at equilibrium.
2025-09-24 - Email Geeks
Achieving Gmail inbox success
Addressing low Gmail open rates and poor inbox placement requires a multi-faceted strategy that covers technical setup, content quality, and continuous monitoring. By ensuring proper email authentication with SPF, DKIM, and DMARC, optimizing your content for size and relevance, and actively cleaning your subscriber lists, you can significantly improve your chances of reaching the Gmail inbox.
Remember, Gmail prioritizes user engagement, so focus on delivering valuable, personalized content that your audience wants to open and interact with. Leverage tools like Google Postmaster Tools and DMARC monitoring from Suped to continuously monitor your performance and adapt your strategies. Consistent effort in these areas will lead to improved inbox placement and better open rates for your Gmail campaigns.
Many email marketers and senders are noticing deflated open rates and a harder time getting emails into the Gmail inbox, based on seed testing and other metrics. This isn't an isolated issue, but rather a reflection of Gmail's continuously evolving algorithms and stricter filtering practices. If your emails are struggling to reach recipients, or if your engagement metrics are declining specifically with Gmail users, it’s crucial to understand the underlying causes and implement effective solutions.
Using a robust DMARC monitoring tool, like Suped, provides visibility into your email authentication status and helps you quickly identify and resolve issues that could be hurting your inbox placement.
Gmail.
