How can newsletter senders improve email deliverability?
Michael Ko
Co-founder & CEO, Suped
Published 14 May 2025
Updated 19 Aug 2025
7 min read
For newsletter senders, reaching the inbox is paramount. It is not enough for your emails to just be sent, they need to actually land where subscribers can see them, otherwise all your hard work on content and design goes to waste. Deliverability is the complex journey your email takes from your server to the recipient's inbox, navigating spam filters, blocklists, and mailbox provider policies. For newsletters, this journey is especially critical, as consistent inbox placement builds subscriber trust and engagement.
Poor email deliverability for newsletters can manifest in several ways: emails landing in the spam folder, being outright rejected, or even disappearing into the void. This not only frustrates your subscribers but also damages your sender reputation, making it even harder to reach the inbox in the future. I often see newsletter creators struggling with this, wondering why their carefully crafted messages aren't reaching their audience.
The good news is that email deliverability is not a mystery, but a science. By understanding the key factors that influence inbox placement and implementing best practices, newsletter senders can significantly improve their chances of landing in the primary inbox. It involves a mix of technical setup, list management, and content optimization. Let's explore how you can tackle these areas to ensure your newsletters consistently hit their mark.
Establish strong technical foundations
A strong technical foundation is the bedrock of good email deliverability. This begins with properly authenticating your sending domain. Mailbox providers like Google and Microsoft heavily rely on these records to verify that you are who you say you are, preventing spoofing and phishing attempts.
The three main authentication protocols are SPF, DKIM, and DMARC. SPF (Sender Policy Framework) specifies which mail servers are authorized to send emails on behalf of your domain. DKIM (DomainKeys Identified Mail) adds a digital signature to your emails, allowing the receiving server to verify that the email was not altered in transit. Lastly, DMARC (Domain-based Message Authentication, Reporting, and Conformance) leverages both SPF and DKIM to tell receiving servers how to handle emails that fail authentication. For a more detailed guide on these, you can refer to a simple guide to DMARC, SPF, and DKIM.
Implementing a DMARC policy, even starting with p=none for monitoring, is crucial for building and protecting your sender reputation. It signals to mailbox providers that you take email security seriously, which can positively influence your deliverability. You can generate a DMARC record using our free DMARC record generator tool. Additionally, consistent sender identity, using a custom domain rather than generic email addresses, helps build trust and recognition with recipients and mailbox providers alike, as highlighted in this article on email deliverability.
Maintain a clean and engaged subscriber list
Your email list is your most valuable asset, and its health directly impacts your newsletter deliverability. Sending to a list filled with inactive, invalid, or unengaged addresses will quickly tank your sender reputation. A clean list ensures your emails reach real, interested people, minimizing bounces and spam complaints.
The first step is to focus on quality over quantity during subscriber acquisition. Implementing double opt-in (where subscribers confirm their subscription via an email) is highly recommended. This ensures that only genuinely interested individuals are added to your list and helps prevent spam traps or misspelled addresses from contaminating your data. Actively removing inactive subscribers or using re-engagement campaigns is also vital, as unengaged contacts will hurt your deliverability over time.
Beyond cleaning, actively encouraging engagement is crucial. Mailbox providers monitor how subscribers interact with your emails, including opens, clicks, replies, and even if they move your email from spam to inbox. High engagement rates signal that your content is valued and legitimate. Here’s a comparison of practices:
Common pitfalls
Purchased lists: These often contain spam traps, invalid emails, and unengaged users, leading to high bounce and complaint rates.
Single opt-in only: Allows for accidental sign-ups or malicious entries, increasing the risk of low engagement or spam complaints.
Ignoring inactive subscribers: Continuing to send to dormant addresses drags down your overall engagement metrics.
Best practices
Organic list growth: Focus on attracting subscribers who genuinely want your content.
Double opt-in: Verify subscribers' intent and email addresses.
Segmentation can further boost engagement. By targeting smaller, more relevant groups within your list, you increase the chances that recipients will engage with your content. This helps improve sender reputation and overall deliverability, particularly for platforms like Yahoo and Hotmail. Additionally, including a clear unsubscribe link is essential, as it provides an alternative to recipients marking your emails as spam, which is far more damaging to your reputation. More on this can be found in a guide to improving email deliverability.
Optimize content and sending practices
The content of your newsletter and how you send it plays a significant role in deliverability. Spam filters are sophisticated and analyze various elements of your email, from subject lines to images and links. Crafting high-quality, relevant content that your subscribers genuinely want to read is key to avoiding the spam folder.
Avoid spammy keywords in subject lines and body text, excessive use of exclamation marks, or large image-to-text ratios. Ensure your links are reputable and not redirecting to suspicious sites. Consistent sending volume is also important. Sudden spikes in email volume can trigger spam filters, as they may indicate a compromised account or a sudden shift in sending behavior. Gradually increase your sending volume for new IPs or domains (a process known as IP warmup).
Monitoring your deliverability is an ongoing process. Keep an eye on your bounce rates, complaint rates, and open/click-through rates. These metrics provide valuable insights into your sender reputation and how your emails are performing. If you notice a sudden drop in deliverability or an increase in spam complaints, investigate immediately. Tools like blocklist monitoring are also crucial, as being listed on a major blacklist can severely impact your ability to reach the inbox. You can check your status with a blocklist checker.
Below is a table summarizing key content and sending best practices:
Aspect
Best practice for newsletters
Content quality
Provide value, be relevant to your audience, and avoid spammy triggers.
Sender name and address
Use a recognizable From name and a consistent domain (not a shared generic one).
Sending volume
Maintain a consistent sending schedule and volume. Warm up new IPs/domains gradually.
Monitoring
Regularly check deliverability metrics and monitor for blocklist (or blacklist) presence.
By proactively managing these aspects, newsletter senders can significantly improve their inbox placement rates and ensure their valuable content reaches its intended audience.
Views from the trenches
Best practices
Always prioritize building a clean and engaged email list through ethical opt-in methods.
Implement strong email authentication (SPF, DKIM, DMARC) from the start to establish trust.
Regularly monitor your sender reputation and deliverability metrics, like open rates and spam complaints.
Segment your audience and personalize content to increase relevance and engagement.
Provide clear and easy unsubscribe options to prevent spam reports.
Common pitfalls
Sending to inactive subscribers or purchased lists, which can damage your sender reputation.
Ignoring bounce rates and spam complaints; these are critical signals of deliverability issues.
Having inconsistent sending volume or sudden spikes, which can trigger spam filters.
Using generic 'From' addresses or domains that don't match your brand.
Failing to implement or correctly configure email authentication protocols.
Expert tips
Warm up new sending IPs and domains gradually to build a positive sending history.
Utilize Google Postmaster Tools and similar services to gain insights into your domain reputation.
Analyze engagement metrics beyond opens, like click-through rates, to understand subscriber interest.
Actively encourage subscribers to whitelist your email address or add you to their contacts.
Periodically review your email content for elements that might trigger spam filters.
Expert view
Expert from Email Geeks says a good starting point for smaller publishers struggling with deliverability is to ensure they have their technical setup correct, especially authentication. It's foundational.
2023-08-23 - Email Geeks
Marketer view
Marketer from Email Geeks says they found that using UT
Ms for tracking engagement in their newsletters helped them understand what content resonated most with subscribers, indirectly boosting deliverability through better engagement.
2023-08-24 - Email Geeks
The path to inbox success
Improving email deliverability for newsletters is a continuous effort, not a one-time fix. It requires a holistic approach that integrates technical setup, vigilant list management, and strategic content creation. By focusing on these core areas, you can significantly enhance your chances of consistently landing in the inbox.
Remember, your sender reputation is built over time through consistent positive sending behavior and subscriber engagement. Every email you send contributes to this reputation. By adhering to best practices, you build trust with mailbox providers and, most importantly, with your subscribers, ensuring your newsletters remain a valuable and reliable channel for communication.
Stay proactive, monitor your performance, and adapt your strategies as needed. The digital landscape and email provider rules evolve, so staying informed and agile will always serve you well in the quest for optimal inbox placement. This dedication ensures your newsletter reaches its audience effectively, maximizing its impact and value.
Google and 
Microsoft heavily rely on these records to verify that you are who you say you are, preventing spoofing and phishing attempts.
Yahoo and 
Hotmail. Additionally, including a clear unsubscribe link is essential, as it provides an alternative to recipients marking your emails as spam, which is far more damaging to your reputation. More on this can be found in a guide to improving email deliverability.
