How to Recover Your Email Deliverability and Sender Score

If your email metrics are tanking — low open rates, high bounce rates, and rising unsubscribe rates — you’re not alone.  

Many marketing teams face the same challenge: the emails they’ve invested valuable time in aren’t reaching their audience. 

Poor email deliverability can lower your credibility, waste resources, and undercut your revenue efforts. The good news? You can always turn things around.  

In this guide, we’ll walk through why email deliverability issues occur, the impact that it has on your business, and how to rebuild your sender reputation with sustainable, strategic fixes. 

What are the signs of poor email performance and deliverability? 

If you’re seeing any of these red flags in your email metrics, it’s a sign that your performance is taking a hit – and as a result – your sender reputation is as well.   

• High Bounce Rates: Sending emails to invalid or outdated addresses damages your sender reputation and tells email providers that your list isn’t well-maintained. 

• Low Engagement: Consistently low open and click rates signal that your content isn’t resonating with recipients, which can affect inbox placement. 

• High Unsubscribe Rates: A spike in unsubscribe rates indicates that your content isn't meeting the expectations or interests of your audience. This can lead email service providers (ESPs) to view your messages as less relevant or potentially intrusive, reducing the likelihood of landing in the primary inbox. 

• Spam Complaints: If recipients flag your emails as spam, inbox providers may divert your future messages to junk folders, reducing your chances of being seen. 

Beyond metrics, certain actions and habits can directly impact your email performance and sender score—sometimes without teams even realizing it. Be aware of the following practices, as they can significantly influence how inbox providers treat your emails: 

• Poor Segmentation: Sending generic messages to your entire list without considering interests or engagement can lead to unsubscribes and decreased interaction. 

• Sudden High-Volume Sends: Rapidly ramping up email volume—especially after switching marketing tools or using a new domain—can trigger ESP filters. Warming up your email domain gradually helps build credibility. 
• Missing Authentication: Without essential authentication protocols like SPF, DKIM, and DMARC, email providers may not trust your messages, increasing the chance they’ll be blocked or sent to spam. 

How to Monitor Performance Using HubSpot 

To better understand what's working—and what’s not—use the “Analyze” tab in HubSpot’s email tool. This dashboard gives you a clear, organized view of key metrics, allowing you to identify trends and troubleshoot issues early. You can: 

• Track open rates, click-through rates, bounce rates, unsubscribes, and spam complaints 

• Filter by campaign, timeframe, or email type to pinpoint performance patterns 

• Compare different email types (e.g., newsletters vs. promotions) 

• Spot red flags like rising bounce rates or drops in engagement 

• Make data-informed adjustments to content, timing, or segmentation 

Checking this dashboard regularly helps ensure your email strategy stays on track—and your deliverability doesn’t suffer. 

Understanding Email Health vs. Email Performance 

Tracking how individual emails perform is key—but to improve deliverability, you also need to monitor your overall email health. 

Email Performance focuses on specific sends, using metrics like: 

• Open and click rates 

• Unsubscribes 

• Bounce rates 

Email Health measures how inbox providers view your overall email practices. It’s influenced by: 

• Engagement consistency 

• Bounce and spam complaint rates 

• List hygiene and send patterns 

Poor email health can lead ISPs like Gmail or Yahoo to route your emails to spam—or block them completely. To manage this, HubSpot includes an Email Health tool that evaluates your deliverability across all of your campaigns. 

It scores your overall email program based on key indicators like engagement, bounces, and complaints. Use this feature regularly to catch deliverability issues early and adjust strategy before performance drops.

Why does email deliverability and sender score matter? 

Email is one of your most scalable, cost-effective marketing tools — when it works. But when messages land in spam or go unopened, you’re not just losing engagement. You’re losing real business opportunities. 

When emails don't get delivered: 

• You don’t drive traffic to your website 

• You don’t generate leads or MQLs 

• You don’t influence revenue 

And that’s a marketing ROI problem.

Proven Steps to Rebuild Your Reputation 

1. Start with a Tiered Audience Strategy 

One of the most effective ways to improve your domain health is to send emails only to your most engaged contacts first. This strategy signals to Email Service Providers (ESPs) that your domain is legitimate and not a spam bot. 

To do this effectively, categorize your audience into engagement tiers based on their interactions: 

• Tier 1: Highly engaged contacts who open and click frequently. 

• Tier 2: Moderately engaged contacts showing occasional activity. 

• Tier 3: Low engaged contacts rarely open or click, signaling a risk of disengagement. 

• Tier 4: Inactive contacts haven’t opened or clicked in months, potentially lost interest. 

Start by emailing Tier 1 only. ESPs value engagement — a small group of highly active recipients builds credibility. Gradually “sprinkle in” lower tiers as your performance improves. 

Tip: Think of this like warming up your IP. The smaller the batch, the higher your success rate. 

2. Scrub Your List with Validation Tools 

Your email list is the foundation of your deliverability. If it’s filled with outdated, incorrect, or inactive addresses, you’re harming your sender reputation. Use email validation tools like ZeroBounce or NeverBounce to remove invalid or dormant contacts. It’s affordable and effective; a clean list means fewer bounces and stronger signals to ESPs that you’re a trusted sender. 

3. Gradually Increase Sending Volume 

Email recovery is not a sprint — it's a marathon. Slowly scale up your sends as your open and click rates improve. Monitor engagement every step of the way and pull back if your performance dips. 

4. Segment and Personalize Your Campaigns 

Generic blasts don’t work anymore. Tailor your emails based on: 

• Engagement level 

• Demographics 

• Behavioral data 

• Customer lifecycle stage 

Use storytelling or technical formats depending on the audience’s buying persona.  

The goal: make every email feel like it was written just for them. 

5. Craft Intentional, Actionable Emails 

One of the most common (but overlooked) issues behind poor email performance is sending messages without a clear purpose or strategy. To truly engage your audience and improve deliverability, focus on creating emails that are clear, relevant, and actionable. 

• Write curiosity-piquing subject lines that spark interest. 

• Craft short, compelling copy that gets to the point and aligns with your audience’s interests. 

• Use strong, inviting calls to action (CTAs) that clearly guide readers on what to do next. 

But even with the best-crafted emails, engagement can vary. That’s why it’s essential to test and learn (A/B tests). Low engagement isn’t always a deliverability issue; sometimes it’s about refining your creative approach. 

Experiment with: 

• Subject lines and preview text to capture attention. 

• Copy tone and structure, from conversational to technical. 

• Visual vs. text-based layouts to see what resonates best. 

• Send times and days to match your audience’s behavior. 

Regular A/B testing helps you discover what truly connects with your readers, allowing you to adjust your strategy and see steady improvements. 

6. Authenticate Your Domain 

To improve trust with email providers and protect against spoofing, ensure your domain has the following: 

• SPF (Sender Policy Framework) – Confirms that emails are sent from an authorized mail server. 

• DKIM (DomainKeys Identified Mail) – Digitally signs emails to verify authenticity and prevent tampering. 

• DMARC (Domain-based Message Authentication, Reporting & Conformance) – Helps monitor and enforce authentication policies. 
  

Start Small and Build 

Improving email deliverability isn’t about chasing perfection—it’s about steady progress. Just like training for a marathon, it requires consistent effort, monitoring, and gradual progress. 

Start by establishing a baseline for key metrics like open rates, click-through rates, bounce rates, and spam complaints. From there, track your improvements tied to each tactic you implement. Aim for consistent open rates of 20–30%, but celebrate small wins along the way—like seeing a 50% open rate on a re-engaged segment. 

Monitor not just engagement, but also the business impact, such as the number of new deals or revenue generated. Start implementing these strategies today, and with patience and persistence, you’ll see your email performance improve over time! 

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