Even the best-crafted email won’t generate results if it lands in the spam folder. Deliverability is the backbone of successful email marketing, and it’s one area where even experienced marketers struggle.
The good news? With the right techniques, you can dramatically improve MailerLite deliverability and secure a spot in your subscribers’ primary inbox. From technical setup to content tweaks, there are proven steps to fix common issues and boost performance.
In this guide, we’ll cover the 10 most effective MailerLite deliverability fixes to help you maximize open rates, increase engagement, and ensure every campaign has a chance to shine.
Why Deliverability Matters in Email Marketing
Email marketing remains one of the highest ROI channels in 2025, but its success depends on a single critical factor—deliverability. No matter how compelling your subject line, design, or offer may be, your email campaign fails if it never reaches the subscriber’s inbox. Deliverability is the invisible gatekeeper between your brand and your audience, and overlooking it can cost you both revenue and reputation.
Think of deliverability as more than just “sending emails.” It’s the science of inbox placement—ensuring that your carefully crafted campaigns don’t end up in spam folders or vanish into the digital void. Studies show that even a small drop in inbox placement can have a massive impact on performance. According to recent industry benchmarks, for every 1% decrease in deliverability, businesses lose an average of 6% in potential email-driven revenue. That means if your list generates $50,000 per campaign, poor deliverability could silently drain thousands of dollars.
The link between inbox placement and ROI is undeniable. When your messages consistently land in the primary inbox, you achieve higher open rates, stronger engagement, and ultimately, better conversions. On the other hand, when deliverability suffers, your brand image takes a hit. Subscribers stop trusting your emails, engagement plummets, and Internet Service Providers (ISPs) flag you as a low-quality sender—creating a vicious cycle that’s hard to escape.
Poor deliverability doesn’t just hurt numbers; it damages relationships. Each missed inbox placement represents a lost opportunity to connect with your audience at the right time with the right message. For small and mid-sized businesses relying heavily on platforms like MailerLite, this risk is even greater. Unlike social media algorithms that shift unpredictably, email marketing gives you direct access to your customers—if you can maintain inbox trust.
In short, deliverability matters because it’s the foundation of every successful campaign. Without it, even the best email strategy is powerless. With it, your brand can unlock the full potential of email marketing: consistent engagement, measurable growth, and long-term customer loyalty.
Common Causes of Poor MailerLite Deliverability
If your MailerLite campaigns are underperforming, deliverability issues may be at the root. Many marketers assume that low open rates or high spam complaints are simply due to “bad timing” or “weak subject lines,” but in reality, technical and behavioral factors often play a much bigger role. Understanding the most common causes of poor deliverability is the first step toward fixing them.
Spam trigger words and content mistakes
One of the easiest ways to get flagged by spam filters is through careless content. Emails that rely heavily on salesy trigger words like “Act now,” “Limited offer,” or “100% free” are red flags for mailbox providers. Similarly, excessive punctuation, ALL CAPS subject lines, or too many exclamation marks can make your campaign look suspicious. Even formatting issues—such as broken HTML code or an unbalanced ratio of text to images—can lower your chances of inbox placement.
Authentication setup errors (SPF, DKIM, DMARC)
Deliverability is not only about what you write, but also about how your emails are authenticated. Without proper SPF, DKIM, and DMARC records in place, ISPs cannot verify that your messages are really coming from your domain. This opens the door to spoofing and phishing risks, which results in your emails being flagged or rejected. MailerLite provides built-in guidance for authentication setup, but skipping this step is one of the most common mistakes among beginners.
Low engagement and inactive lists
Mailbox providers such as Gmail, Outlook, and Yahoo increasingly evaluate subscriber behavior when deciding inbox placement. If too many of your recipients ignore your emails, delete them without opening, or mark them as spam, your sender reputation takes a hit. Continuing to email inactive subscribers drags down engagement rates, signaling to ISPs that your campaigns are unwanted. This is why keeping a “clean list” is more than a best practice—it’s a deliverability necessity.
Other overlooked factors
- High bounce rates: Sending to invalid or outdated email addresses tells ISPs your data is poorly maintained.
- Shared IP reputation: If you’re on a shared MailerLite sending IP and other users behave poorly, your inbox placement may be affected.
- Sudden sending spikes: Going from zero to thousands of emails overnight looks suspicious and often results in throttling or spam placement.
When deliverability drops, the consequences ripple across your entire marketing ecosystem. Poor inbox placement leads to lower click-throughs, fewer conversions, and a gradual decline in customer trust. By recognizing these pitfalls early, MailerLite users can take proactive steps to safeguard inbox success.
“Great email content is wasted if it never reaches the inbox—MailerLite deliverability fixes ensure your message gets seen, not spammed.”
10 Fixes for Better MailerLite Deliverability
Now that we’ve covered the common causes of poor deliverability, it’s time to focus on proven solutions. Improving deliverability inside MailerLite doesn’t require advanced technical knowledge—just consistency, best practices, and a willingness to maintain healthy email habits. Here are 10 actionable fixes you can start applying today.
- Verify your domain with SPF, DKIM, and DMARC
The first step is setting up proper email authentication. These protocols confirm to ISPs that your emails are legitimate and not forged. MailerLite provides clear step-by-step guides for connecting SPF, DKIM, and DMARC records to your domain. Once verified, your sender reputation instantly improves, giving your campaigns a stronger chance of landing in the inbox. - Use a dedicated sending domain
While MailerLite allows beginners to send through shared domains, businesses that rely on email for sales should consider setting up a dedicated sending domain (e.g., mail.yourbrand.com). This isolates your reputation from other senders and gives you full control over how ISPs view your messages. - Clean your subscriber list regularly
Deliverability thrives on engagement. Remove inactive subscribers, bounced addresses, and unverified signups at least once every 90 days. MailerLite includes built-in tools for list cleaning, making this process easy to manage without external software. - Avoid spammy subject lines and content
Instead of shouting “Buy Now!!!” in your subject line, focus on clarity and value. Keep your subject lines natural, relevant, and conversational. Use preview text to set clear expectations, and maintain a balanced text-to-image ratio inside the email body. - Warm up your domain gradually
If you’re launching a new MailerLite account or sending from a freshly authenticated domain, don’t blast thousands of emails right away. Start small—send to your most engaged subscribers first, then increase volume gradually over 2–4 weeks. This warms up your domain reputation with ISPs. - Segment your audience for relevance
Not every subscriber should get the same message. MailerLite’s segmentation tools allow you to group subscribers by behavior, location, or interest. Sending tailored campaigns ensures higher engagement, which ISPs interpret as a sign of trustworthiness. - Encourage engagement (clicks and replies)
Ask questions, invite feedback, and include clear calls to action. ISPs track signals such as opens, clicks, and replies to measure subscriber interest. A reply to your email is one of the strongest positive signals for inbox placement. - Balance text-to-image ratio in emails
Emails that are 90% images and only 10% text are often flagged as spam. Aim for a healthy balance (60% text / 40% images) so your emails render correctly across devices and pass spam filters more easily. - Monitor blacklist status and sender reputation
Your sending domain and IP can sometimes appear on blacklists if flagged for spam-like behavior. Tools such as MXToolbox and MailerLite’s built-in reputation reports help you monitor blacklist status and act quickly if issues arise. - Test emails before sending (spam score tools)
Never send blindly. MailerLite integrates with spam-checking tools that evaluate your content before delivery. Testing allows you to fix risky subject lines, broken links, or code issues that could trigger spam filters.
Advanced Tips to Maximize Inbox Placement
Once you’ve mastered the basics of authentication, list cleaning, and engagement, it’s time to move into more advanced strategies. These tactics go beyond fixing mistakes—they help you stay ahead of shifting ISP algorithms and squeeze more value out of your MailerLite campaigns.
Personalization beyond the first name
Most marketers stop at inserting a subscriber’s first name, but personalization in 2025 requires more sophistication. With MailerLite’s dynamic content blocks, you can customize offers, product recommendations, and calls to action based on purchase history, location, or behavior. For example, a clothing retailer might show winter coats to subscribers in Canada while displaying summer dresses to users in Australia—all within the same campaign. The deeper the relevance, the stronger the engagement, which translates into higher deliverability.
Optimize send times based on subscriber activity
Timing matters as much as content. MailerLite tracks subscriber behavior and lets you send campaigns when recipients are most likely to engage. For instance, if data shows your audience typically opens emails at 8:30 AM local time, scheduling sends at that moment increases inbox visibility and engagement. Over time, this boosts your sender reputation because ISPs see that your messages are consistently wanted and opened.
Track deliverability metrics inside MailerLite
Deliverability isn’t static—it changes over time. MailerLite provides real-time reporting on bounce rates, open rates, spam complaints, and click-throughs. Regularly reviewing these metrics helps you spot early warning signs, like a sudden dip in opens or a spike in bounces, so you can fix problems before they escalate. Advanced marketers even integrate MailerLite data with third-party monitoring tools to get a complete picture of domain and IP health.
Pro insights to stay ahead
- Use A/B testing not just for subject lines, but for sender names and content length.
- Experiment with interactive elements (polls, surveys, gamification) to increase clicks and replies.
- Maintain consistent sending frequency—going silent for weeks and then suddenly blasting subscribers often triggers spam filters.
Advanced deliverability optimization is about sending smarter, not just more. By layering these techniques on top of the foundational fixes, MailerLite users can consistently achieve high inbox placement, outperform competitors, and future-proof their email strategy in an ever-evolving digital landscape.
MailerLite Deliverability vs Competitors
With so many email marketing platforms on the market, businesses often wonder: How does MailerLite compare to popular alternatives like Mailchimp, ConvertKit, and ActiveCampaign when it comes to deliverability? The truth is, each platform has strengths, but MailerLite holds its own—especially for small and mid-sized businesses that prioritize simplicity, affordability, and inbox placement.
How MailerLite compares to Mailchimp, ConvertKit, and ActiveCampaign
Mailchimp: Known for its powerful features and brand recognition, Mailchimp performs well on deliverability but can be overwhelming for smaller teams. Its pricing also scales quickly, making it less attractive for budget-conscious marketers. MailerLite, in contrast, offers similar inbox placement rates at a fraction of the cost.
ConvertKit: A favorite among creators and bloggers, ConvertKit is streamlined for automation and audience growth. While its deliverability is strong, it lacks some of MailerLite’s built-in testing and spam-checking tools, meaning marketers must rely on external solutions.
ActiveCampaign: Highly advanced with deep CRM integration, ActiveCampaign excels in segmentation and automation. However, the learning curve is steep, and costs can escalate as lists grow. MailerLite, on the other hand, delivers competitive inbox placement with far less complexity.
Why MailerLite is strong for small and mid-sized businesses
MailerLite shines where it matters most: ease of use and deliverability balance. Setting up SPF, DKIM, and DMARC is straightforward, list-cleaning tools are integrated, and deliverability monitoring is built right into the dashboard. For startups, e-commerce shops, and growing brands, this means less time troubleshooting and more time running campaigns that actually reach customers.
| Feature / Platform | MailerLite ⭐ | Mailchimp ⭐ | ConvertKit ⭐ | ActiveCampaign ⭐ |
|---|---|---|---|---|
| Deliverability Rate (2025 avg.) | 95–97% | 96–98% | 94–96% | 96–98% |
| Ease of Authentication Setup | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★☆ |
| Built-in Spam Testing | ★★★★★ | ★★★☆☆ | ★★☆☆☆ | ★★★★☆ |
| Pricing for 10,000 contacts | Affordable | Higher | Moderate | Higher |
| Best For | SMBs, e-commerce | Agencies, enterprises | Creators, bloggers | Advanced automation users |
Final Thoughts: Winning with Deliverability
Deliverability isn’t just a technical checkbox—it’s the heartbeat of every successful email marketing strategy. No matter how polished your campaigns are, they can’t perform if they’re stuck in spam folders. MailerLite makes the process simpler by combining user-friendly tools with the essential deliverability safeguards businesses need in 2025.
Recap of the 10 fixes
From authenticating your domain with SPF, DKIM, and DMARC, to cleaning your list regularly, segmenting your audience, and testing emails before sending, these steps form the backbone of strong inbox placement. When paired with MailerLite’s built-in features—like list management, spam testing, and deliverability reporting—your campaigns gain a much higher chance of success.
Why consistent monitoring is key
Deliverability isn’t a one-time project. ISPs constantly adjust algorithms, and subscriber behavior evolves over time. That’s why monitoring bounce rates, complaint levels, and engagement trends is just as important as creating great content. With MailerLite, you can track these signals directly and take quick action if numbers start slipping.
How to build long-term inbox trust
The real secret to winning with deliverability is trust—between your brand, your subscribers, and mailbox providers. By sending only to people who want your emails, delivering valuable content, and maintaining a consistent sending schedule, you gradually build a reputation as a reliable sender. Over time, this trust pays off in higher open rates, stronger engagement, and more predictable ROI.
Deliverability is not an afterthought—it’s your ticket to email marketing success. With the right strategy and the right platform, you don’t just avoid spam folders—you build stronger customer relationships and long-term growth.
Shocking Data on Email Deliverability and the Hidden ROI Gap
Most marketers assume that as long as their emails are being “sent,” they’re doing their job. But the reality is far different: deliverability gaps silently drain revenue. A campaign that looks successful on the surface may actually be losing thousands in missed inbox placements. Let’s break this down with a case study, fresh 2025 data, and a reality check on what deliverability really means.
Case Study: From Spam Folder Struggles to Inbox Wins
Situation:
A mid-sized e-commerce brand using MailerLite noticed that despite sending to 50,000 subscribers, open rates were stuck around 12%. Sales from email had plateaued.
Problem:
After an audit, the brand discovered authentication records weren’t fully configured, and 20% of its list was inactive subscribers. Worse, subject lines contained spam-trigger words like “free” and “urgent.”
Steps:
The team verified SPF, DKIM, and DMARC, cleaned their list of unengaged contacts, and began warming their domain. They also rewrote content with natural subject lines and added interactive elements to encourage replies.
Results:
Within 90 days, inbox placement improved from 82% to 96%, open rates climbed to 24%, and revenue from email jumped by 41%.
Data: The Numbers Behind Deliverability in 2025
Industry-wide research in 2025 shows that the average inbox placement rate is 95%, but many businesses unknowingly operate below 85%. According to Email Deliverability Benchmark Reports, every 1% increase in inbox placement delivers an average 6% boost in ROI. For businesses generating $100,000 annually from email, this difference can equal an extra $30,000–$50,000 per year.
Perspective: What People Think vs. Reality
- What people think: Low engagement is caused by poor content, timing, or audience mismatch.
- Reality: In many cases, emails never even reach the inbox. Content is irrelevant if subscribers don’t see it. Authentication failures, inactive lists, and poor sender reputation are the real culprits.
Why:
Mailbox providers prioritize engagement signals and sender trust. Brands that fail to manage deliverability often misdiagnose performance issues, wasting time rewriting copy instead of fixing the real problem.
FAQs
If you’re struggling with MailerLite deliverability or just want to improve your inbox rates, you’re not alone. These are some of the most common questions marketers ask in 2025—along with straightforward answers that can help you take action right away.
The quickest way is to verify your domain with SPF, DKIM, and DMARC, clean your list of inactive subscribers, and avoid spammy subject lines. These three steps alone can significantly improve inbox placement within weeks.
Common reasons include missing authentication, using spam-trigger words, sending to unengaged lists, or sending too many emails at once. MailerLite provides spam testing tools—use them before sending to catch risky elements early.
Yes. MailerLite allows you to configure SPF, DKIM, and DMARC records directly in your domain’s DNS settings. Once properly set up, your emails are authenticated, making it far less likely for them to be marked as suspicious.
At least once every 90 days. Removing inactive subscribers, bounced addresses, and unverified signups not only boosts deliverability but also improves engagement rates, which ISPs use to evaluate sender reputation.
A strong deliverability rate in 2025 is 95% or higher. If your campaigns consistently fall below this benchmark, it’s a sign that something in your setup, content, or list management needs attention.
SEO-Friendly Review
MailerLite deliverability tools in 2025 make it much easier for marketers to keep campaigns out of spam folders and consistently reach the inbox. With authentication support, list-cleaning features, and real-time reporting insights, MailerLite has proven itself as one of the most reliable platforms for inbox success. Here’s a detailed review:
Ease of Setup: ★★★★★
Setting up SPF, DKIM, and DMARC in MailerLite is straightforward, even for beginners. The platform provides step-by-step guides and intuitive DNS instructions, which drastically reduce setup errors. Compared to competitors, the process is faster and less technical, making it ideal for small and mid-sized businesses.
List Management: ★★★★★
MailerLite shines in subscriber management. Its built-in list-cleaning tools help automatically remove bounced addresses and inactive contacts. Segmentation features are robust, allowing marketers to send highly relevant campaigns that boost engagement and, in turn, deliverability.
Spam Protection: ★★★★★
The platform includes spam testing and compliance checks that preview how your campaigns will perform against ISP filters. This reduces the chances of accidentally using trigger words, broken links, or formatting errors that could send emails straight to spam.
Deliverability Performance: ★★★★★
With proper authentication and best practices, MailerLite consistently achieves inbox placement rates above 95%. This rivals more expensive competitors like Mailchimp and ActiveCampaign, proving that affordability doesn’t mean sacrificing performance.
Overall Value: ★★★★★
For businesses that rely heavily on email marketing, MailerLite offers powerful deliverability tools at an affordable price point. The platform balances simplicity with reliability, ensuring that campaigns reach subscribers without requiring advanced technical expertise.
Conclusion
MailerLite deliverability in 2025 proves that inbox placement is the foundation of email marketing success. To consistently win with your campaigns, you need to focus on three main points:
- Authentication and Setup: Verifying your domain with SPF, DKIM, and DMARC builds instant trust with ISPs and prevents your emails from being flagged as suspicious.
- List Quality and Engagement: Cleaning your lists, segmenting subscribers, and encouraging clicks or replies are the strongest signals that your emails are valuable.
- Ongoing Monitoring: Deliverability isn’t static. Tracking performance metrics, testing campaigns before sending, and monitoring blacklist status are essential for long-term inbox placement.
The answer to the main question—how do you achieve better MailerLite deliverability?—is simple: combine technical setup with smart engagement strategies and consistent monitoring. By doing this, your emails don’t just avoid spam—they build trust, drive revenue, and strengthen customer relationships.
If you’ve found these insights helpful, share this article with other marketers. The more we prioritize deliverability, the stronger email marketing becomes as a channel in 2025 and beyond.