Email deliverability is an important factor in determining whether your messages land in subscribers' inboxes or spam folders. When deliverability rates drop, companies waste effort, lose revenue, and damage their sender reputation.
Want to rescue your business newsletter from the spam folder? Let’s look at 11 proven ways to improve your email deliverability rates and help your messages reach their destination consistently. We’ll cover everything from maintaining email lists to implementing testing protocols to place your emails right where they belong — your leads’ primary inbox.
Table of Contents
- Maintain a Clear Email List
- Authenticate and Warm Up Your Domain
- Focus on Content Quality
- Balance AI-Generated Content
- Monitor Sender Reputation
- Engage Your Audience
- Comply with Email Regulations
- Ensure Mobile Responsiveness
- Define Timing and Frequency
- Monitor Email Metrics
- Test Before Hitting Send
- Improve Email Deliverability: The Bottom Line
- Improve Email Deliverability FAQs
1. Maintain a Clear Email List
A clean email list is essential for healthy growth and optimal results. Your email list is the foundation of your email marketing success because it directly connects you with an audience that has opted in to hear from you, making them more likely to engage, convert, and build loyalty. Maintaining it properly is crucial to improve email deliverability.
Here's how to keep your email list pristine:
- Remove inactive subscribers after 6-12 months
- Implement double opt-in for new subscribers
- Regularly clean bounced and invalid emails
- Use list segmentation based on engagement
- Remove role-based emails (info@, admin@, etc.)
When you send emails to engaged subscribers who want to hear from you, email providers take notice. They see that your messages are welcomed and valued, which boosts your sender reputation.
Don't hesitate to let go of unengaged subscribers. While it might feel counterintuitive to reduce your list size, remember that quality always trumps quantity in email marketing. A smaller, engaged list will yield better results than a large, unresponsive one.
Make it easy for subscribers to update their preferences or unsubscribe. This self-cleaning mechanism helps maintain list hygiene naturally and shows respect for your subscribers' choices.
Remember to validate email addresses at the point of collection. This simple step prevents typos and fake emails from entering your list in the first place, saving you cleanup work later.
2. Authenticate and Warm Up Your Domain
Think of domain authentication as getting a verified badge for your email-sending identity. Just as you wouldn't trust a stranger at your door without proper ID, email providers must verify your legitimacy before delivering your messages to their users' inboxes.
Implementing domain authentication is one of the essential email deliverability best practices, ensuring your messages reach their intended recipients and don’t get flagged as spam.
To properly authenticate your domain, implement these essential protocols:
- Sender Policy Framework (SPF) records
- DomainKeys Identified Mail (DKIM) signatures
- Domain-based Message Authentication (DMARC) policy
Warming up your domain takes time and consistency. Start by sending small volumes of emails (around 50-100 per day) to your most engaged subscribers. Gradually increase your sending volume over 4-6 weeks while maintaining high engagement rates.
Remember to maintain consistent sending patterns during warm-up. Sudden spikes or irregular sending patterns can raise red flags with email providers and potentially harm your deliverability rates.
3. Focus on Content Quality
Quality content is one of the most important email marketing best practices. While technical setup matters, what's inside your email is crucial in determining whether it lands in the primary inbox or gets filtered as spam.
Create content that resonates with your audience. When your content connects with readers, they're more likely to engage with it, which signals to email providers that your messages are valuable.
The key elements to focus on for better deliverability:
- Keep your word choice professional and avoid spam trigger words (for example, Free, Earn cash, Best price, etc.)
- Use clean code with properly closed tags
- Include only legitimate links to reputable websites
- Make content visually appealing and easy to scan
Your subject lines deserve special attention because they determine whether your email gets opened, directly impacting your efforts to increase email deliverability. While catchy phrases might be tempting, avoid using common spam phrases or overly promotional language. Instead, convey genuine value that makes readers want to open your message.
Keep your subject lines clear, concise, and engaging by focusing on relevance, curiosity, urgency, personalization, and brevity, such as "Exclusive Tips to Boost Your Productivity" or "Last Chance: 24 Hours to Save 20%."
Email providers use sophisticated filters to evaluate your content quality. These filters check everything from word choice to code structure, determining whether your message deserves prime inbox placement. By maintaining high content standards, you're not just pleasing your readers — you're also building trust with email service providers.
4. Balance AI-Generated Content
While artificial intelligence (AI) tools are reshaping email marketing, you must balance automation and human touch to maintain strong deliverability rates.
AI should enhance your email marketing efforts, not completely take over. Recent studies show that well-crafted AI emails can achieve higher engagement rates when following best practices.
Here's how to effectively balance AI in your email content:
- Use AI for initial drafts and ideas
- Always edit and customize AI-generated content
- Maintain your brand's unique voice
- Add personal touches to automated messages
- Double-check for relevance and accuracy
There's no evidence that properly crafted AI-generated emails are more likely to be marked as spam. However, if your AI tool was trained on spam-like content, it might produce emails that trigger spam filters. That's why human oversight remains essential.
5. Monitor Sender Reputation
Your reputation determines whether your messages reach the inbox or get flagged as spam. As you monitor your credit score, keep tabs on your sender reputation to maintain strong email deliverability.
Key metrics to monitor:
- Bounce rates and complaint rates
- Engagement levels (opens, clicks)
- IP and domain reputation scores
- Blocklist status
- Spam trap hits
Google Postmaster Tools and Microsoft SNDS provide valuable insights into how major email providers view your sending practices. Gmail, for instance, uses sophisticated algorithms to assess your reputation and determine inbox placement.
Your domain reputation impacts email deliverability across all platforms and providers, so it's essential to track both IP and domain performance. When recipients engage positively with your emails, your sending reputation improves, making future messages more likely to reach the inbox.
For instance, if your cumulative open rate consistently falls below 10%, it's time to limit your sending volume and focus on repairing your reputation. High bounce rates or spam complaints can quickly damage your sender score, so monitor these metrics closely.
6. Engage Your Audience
Engaging your audience is key to increasing email deliverability and consistently landing in the inbox. When subscribers actively interact with your emails, providers see these positive signals and boost your deliverability rates.
By segmenting your email list based on subscriber behavior and preferences, you can increase open rates by up to 203%. Personalization should go beyond just using first names — tailor your message to match your audience's interests and needs.
Here are proven strategies to boost engagement:
- Create targeted content for different subscriber segments
- Use dynamic content that adapts to user preferences
- Include interactive elements like polls or quizzes
- Send behavior-triggered emails
- Craft personalized subject lines and preview text
Deliver value in every email. Your subscribers are more likely to engage when they know each message will be worth their time. Track which content types generate the most interaction and use these insights to refine your strategy. This data-driven approach helps maintain strong engagement rates while improving your email deliverability.
7. Comply with Email Regulations
Complying with email regulations is important for maintaining strong deliverability rates, as it safeguards your business and protects your sender reputation.
As Denisa Mihaela Chiscop, Head of Marketing Automation at eCommerce Today, notes: "As phishing grows, users are more cautious about unsolicited emails. To avoid being flagged as phishing attempts, brands must ensure clear branding, authentication, and trusted sending practices. "
The CAN-SPAM Act sets the foundation for commercial email practices in the USA, with penalties reaching up to $51,744 per violation. To keep your email program compliant:
- Include accurate header and routing information
- Write honest subject lines that reflect email content
- Identify commercial messages as advertisements
- Include your physical business address
- Provide clear opt-out instructions
- Honor unsubscribe requests within 10 business days
- Monitor third-party compliance when outsourcing
For European audiences, the General Data Protection Regulation (GDPR) adds another layer of requirements. You must obtain explicit consent before sending marketing emails and maintain detailed records of how and when this consent was given.
Compliance isn't optional — it's a fundamental part of email deliverability. Each separate email violation can result in significant penalties, making it crucial to establish proper procedures before launching your email campaigns.
If you're reaching an international audience, familiarize yourself with local regulations like Canada's anti-spam legislation (CASL) and the UK's privacy and electronic communications regulations (PECR). These laws share common themes around consent and transparency but may have specific requirements you'll need to address.
8. Ensure Mobile Responsiveness
Your email should maintain its visual appeal and functionality, whether viewed on a smartphone during a commute or on a desktop at work. With over half of all emails being opened on mobile devices, responsive design is crucial, as Paul Feith, President of Paul Gregory Media, emphasizes.
Make your emails mobile-ready:
- Use a responsive design that adapts to screen sizes
- Implement single-column layouts for easy reading
- Set larger font sizes for better visibility
- Create touch-friendly buttons
- Include adequate white space around clickable elements
- Optimize images for faster loading
Email providers consider user experience when determining inbox placement. When recipients struggle to read your emails on mobile devices, they're more likely to delete them without reading them — or worse, mark them as spam.
Responsive design isn't just about shrinking content — it's about creating an experience that feels natural on any device. Feith adds: “The rising popularity of dark mode on devices requires email designs that adapt to both light and dark backgrounds to ensure readability and a positive user experience.”
9. Define Timing and Frequency
Research shows that Tuesday and Thursday are your golden days for email sending, as emails during these days account for the highest share of opens. The sweet spot? Between 10 AM and 3 PM, when your subscribers are most likely to engage with their inbox.
Best practices for email timing:
- Send during weekdays
- Test mid-morning (10 AM) and mid-afternoon (3 PM) slots
- Avoid sending at exact hour marks to prevent inbox competition
- Consider time zones for international audiences
- Maintain consistent sending patterns
Your audience type matters, too. B2B emails typically perform better during work hours, while B2C messages might increase engagement during evenings or weekends. The key is understanding your specific audience's habits and testing different times to find what works best.
Stay consistent with your chosen schedule. If you go months without sending, subscribers may forget who you are and be more likely to mark you as spam.
10. Monitor Email Metrics
Source: Octoboard
By monitoring the right metrics, you'll know exactly when to adjust your strategy to maintain optimal inbox placement.
Here are the essential metrics to track:
- Click-through rate (CTR): The percentage of recipients who clicked links in your email. Aim for rates above 1% across industries
- Open rate: While less reliable due to privacy changes, open rate is still useful for trending. Target above 33% for healthy engagement
- Bounce rate: Keep below 1% to protect your sender reputation
- Spam complaint rate: Should stay under 0.01% per mailbox provider
- Unsubscribe rate: Maintain below 0.3% per campaign
Also, a good average email deliverability hovers around 90% to 98%.
Your email service provider's dashboard is your command center for these metrics. Regular monitoring helps you spot potential issues before they become critical. For instance, if you notice a sudden spike in bounce rates, you can quickly clean your list before it damages your sender reputation.
Review your metrics at least weekly, paying special attention after major campaigns or changes to your email strategy. These numbers aren't just statistics — they're direct feedback from your subscribers about the value and relevance of your messages.
11. Test Before Hitting Send
Before launching your email campaign, prioritize comprehensive testing. With email clients updating display preferences every 1.2 days and over 300,000 different ways for your email to display, testing ensures your emails render correctly across devices and platforms, preventing costly errors.
Essential pre-send checklist:
- Verify all links are working and properly tracked
- Check image loading and alt text
- Test subject lines and preview text
- Review mobile responsiveness
- Run spam filter checks
- Validate email rendering across clients
Your emails could look strange in subscribers' inboxes without you noticing. That's why testing every email before sending is non-negotiable — even if you used the same template yesterday.
For the most reliable results, send test emails directly from your service provider to check how they'll appear to recipients. Pay special attention to your from name, reply-to address, and preview text optimization — these elements significantly impact deliverability.
Running spam tests before every send helps identify issues that could cause your email to be flagged as spam, such as problematic content, formatting errors, or blacklisted domains, ensuring better deliverability and protecting your sender reputation.
Improve Email Deliverability: The Bottom Line
Email deliverability success requires attention to multiple crucial elements. Partnering with an experienced email marketing agency can streamline this process, ensuring each step — from maintaining clean lists to implementing proper authentication protocols — is executed effectively to maximize your chances of reaching the intended destination.
Make email deliverability improvement an ongoing priority rather than a one-time fix. Small, consistent actions like list cleaning, content optimization, and regular testing create a significant positive impact over time. Start implementing these proven strategies today and watch your email performance steadily climb as you build stronger connections with your audience.
Improve Email Deliverability FAQs
1. How often should I send emails?
The sweet spot is typically one or two emails per week. This frequency helps maintain engagement without overwhelming your subscribers.
2. What elements make an email look "spammy?"
Avoid overusing words like "free," "promo," and "buy" in subject lines. Keep your image-to-text ratio balanced and maintain an email size of around 30KB. Remember that each ISP has unique standards for filtering spam.
3. What are spam traps, and why should I care?
Spam traps are email addresses created or repurposed by blocklist operators and ISPs to identify spam senders. Getting caught in these traps can seriously damage your sender reputation and deliverability rates.
