How to improve Gmail deliverability for a gambling/fantasy league newsletter with a history of deliverability issues?
Michael Ko
Co-founder & CEO, Suped
Published 11 Aug 2025
Updated 16 Aug 2025
6 min read
Improving Gmail deliverability for a newsletter, especially one in the gambling or fantasy league industry, presents unique challenges. When there's a history of deliverability issues, it suggests underlying problems beyond a simple IP change. Even on a pristine shared IP, your domain's sending history and recipient engagement heavily influence where your emails land. It's not just about the reputable sending domain but the entire sending ecosystem.
The transition to a new platform and IP is an opportunity for a fresh start, but it doesn't automatically erase past reputation. Gmail considers a combination of factors, including domain reputation, sender behavior, and user engagement metrics. Without addressing these, bulking to spam or the promotions tab will likely persist. A strategic approach is required to systematically rebuild trust with Gmail's filtering algorithms.
Diagnosing the root causes
The first step in any deliverability improvement plan is to understand where the current issues stem from. While a new IP can help, if your domain has a poor reputation from previous sending, that history will follow you. Gmail heavily weighs domain reputation over IP reputation, especially for bulk senders.
A critical tool for diagnosis is Google Postmaster Tools. This free service provides detailed insights into your sending performance, including IP and domain reputation, spam rates, feedback loop data, and authentication errors. Setting this up promptly will give you the data needed to make informed decisions.
Even for a shared IP with high volume, Google's algorithms will differentiate traffic based on the sending domain. If the domain's past behavior (e.g., high spam complaints, low engagement, high bounces) has flagged it, the emails will continue to be affected regardless of the IP's overall reputation. This is why a domain-level reset or a deliberate reputation-building strategy is essential.
Utilizing Google Postmaster Tools
Google Postmaster Tools provides essential dashboards for monitoring your email performance with Gmail. These insights are crucial for understanding the root cause of deliverability issues.
IP and domain reputation: These scores reflect how Gmail perceives your sending practices. A low reputation leads to bulking.
Feedback loop: This data shows when users mark your emails as spam, allowing you to remove those addresses.
Delivery errors: Identify issues like rate limiting or content-based rejections.
Rebuilding your sending reputation
Given the history of issues and the sensitive nature of gambling/fantasy league content, rebuilding sender reputation is paramount. This starts with aggressive list hygiene and a strong focus on engagement. Since a majority of subscribers come from in-app sign-ups, you have an advantage with initial engagement, but this can quickly fade if content isn't relevant or if expectations aren't managed.
Start by segmenting your list. For the initial sends, target only your most engaged subscribers, especially those who have opened emails since the platform switch. This allows you to generate positive engagement signals with Gmail and Yahoo Mail before expanding to less active segments. A small, focused warmup targeting Gmail users specifically, combined with this engagement-based segmentation, can be beneficial to demonstrate consistent positive behavior to their algorithms. For more in-depth guidance, see how to improve your domain reputation with Gmail.
For dormant subscribers or those whose engagement data you don't have, consider a re-engagement campaign outside of the main sending stream. If you have non-email contact methods (e.g., in-app notifications), use them to prompt users to check their spam or promotions folders and move your emails to the inbox. This manual intervention by users is a powerful positive signal to Gmail.
Immediate Actions for Reputation Repair
Segment your list: Send only to highly engaged subscribers initially.
Gradual ramp-up: Slowly increase sending volume to broader segments as reputation improves.
Content refinement: Review and optimize email content to avoid spam triggers, especially given the industry.
In-app prompts: Encourage users to move emails from spam/promotions to their primary inbox.
Long-Term Strategies for Domain Health
Consistent list cleaning: Regularly remove unengaged subscribers and invalid addresses.
Monitor feedback loops: Act quickly on spam complaints by removing those users.
Maintain engagement: Send relevant content that your audience wants to open and click.
Consider domain change: As a last resort, if the domain reputation is severely damaged, consider a new sending domain. See how to recover sender reputation.
Technical foundations and content considerations
Beyond reputation, ensuring your technical setup is flawless is non-negotiable for Gmail. This means correctly configuring SPF, DKIM, and DMARC. These authentication protocols tell mailbox providers that your emails are legitimate and prevent spoofing. Even if your emails land in the spam folder, a lack of proper authentication makes it much harder for them to reach the inbox. You can learn more in a simple guide to DMARC, SPF, and DKIM.
Content also plays a huge role. For newsletters in the gambling or fantasy league niche, certain keywords or phrases might trigger spam filters more readily. Avoid overly promotional language, excessive capitalization, or aggressive calls to action. Focus on delivering value and information that subscribers genuinely expect from a fantasy league advice newsletter. Personalized content can also improve engagement.
Email design and coding should be clean and responsive. Heavy use of images without alt text, broken HTML, or excessive embedded elements can also negatively impact deliverability. Test your emails across different clients and devices to ensure they render correctly and load quickly.
Deliverability is an ongoing process, not a one-time fix. Continuous monitoring of your metrics is crucial. Keep a close eye on your Gmail deliverability rates, open rates, click-through rates, and, most importantly, complaint rates. High complaint rates are a red flag that will quickly land your emails in the spam folder or on a blacklist (or blocklist). For more, read about what happens when your domain is on a blacklist.
If bulking persists, consider reaching out to Gmail support for bulk senders. While not a magic fix, submitting a detailed request can sometimes provide clarity or help expedite reputation recovery. Be prepared to provide data and details about your sending practices.
Regular A/B testing of subject lines, content variations, and send times can also reveal what resonates best with your audience and improve engagement metrics. For a newsletter that sends 2-4 times a week during peak season, optimizing every touchpoint is crucial to maintain positive signals with Gmail and avoid future deliverability issues.
Metric
Target goal
Impact on Gmail deliverability
Spam complaint rate
Below 0.1%
High rates severely damage domain reputation.
Hard bounce rate
Below 0.5%
Indicates invalid addresses, can lead to spam trap hits.
Open rate
As high as possible, compare to industry average
Low open rates signal lack of interest, impacting sender reputation.
Click-through rate
As high as possible, compare to industry average
Reflects content relevance and engagement, a positive signal.
Views from the trenches
Best practices
Focus on sending to engaged subscribers first to rebuild reputation with mailbox providers.
Use Google Postmaster Tools to regularly monitor your domain and IP reputation.
Implement and maintain robust email authentication: SPF, DKIM, and DMARC.
Segment your list based on engagement and gradually expand your sending audience.
Provide clear unsubscribe options and honor requests promptly to minimize spam complaints.
Common pitfalls
Relying solely on a new shared IP to fix existing domain reputation issues.
Failing to clean your email list of unengaged or invalid addresses.
Sending inconsistent content or too frequently, leading to low engagement.
Ignoring feedback loop data, which indicates spam complaints from users.
Using generic or spam-triggering subject lines and email body content.
Expert tips
If your domain reputation is severely damaged, consider setting up a new sending domain as a last resort.
Leverage non-email channels, such as in-app notifications, to prompt users to engage with your emails.
Analyze your email content for elements that might be triggering spam filters, especially given the industry.
Continuously test subject lines and content to find what resonates best with your audience.
Understand that rebuilding reputation takes time and consistent effort, often several weeks or months.
Expert view
Expert from Email Geeks says a domain reputation issue due to low engagement is a likely culprit. It is advisable to pull back to engaged or newest subscribers for a few weeks to improve the situation.
2021-12-10 - Email Geeks
Marketer view
Marketer from Email Geeks says domain issues are a significant concern for deliverability.
2021-12-10 - Email Geeks
The path forward
Improving Gmail deliverability for a gambling/fantasy league newsletter with a history of issues is a complex but achievable goal. It requires a multifaceted approach that addresses both historical reputation and current sending practices. By prioritizing audience engagement, meticulously cleaning your list, ensuring technical compliance, and continuously monitoring performance, you can gradually rebuild trust with Gmail.
Remember, email deliverability is a marathon, not a sprint. Consistent adherence to best practices, coupled with a willingness to adapt based on data, will pave the way for successful inbox placement and sustained engagement with your subscribers. The goal is not just to avoid the spam folder, but to foster a healthy, reciprocal relationship with your audience, ensuring your valuable content reaches them consistently. You can also explore general steps to improve Gmail deliverability.
