How can I improve my email and domain reputation and overall deliverability?
Matthew Whittaker
Co-founder & CTO, Suped
Published 23 May 2025
Updated 17 Aug 2025
7 min read
Dealing with a damaged email and domain reputation can feel like an uphill battle. When past sending practices have negatively impacted your standing, it affects everything from inbox placement to overall marketing effectiveness. It's a common scenario, especially when inheriting a system where previous high-volume, unchecked sending led to significant issues. The good news is that reputation can be rebuilt, but it requires a strategic and patient approach.
I've seen many organizations go through this, moving from millions of emails sent monthly with poor results to a more controlled, reputation-focused volume. The goal isn't just to reduce sends, but to ensure the emails you do send reach their intended recipients, thereby improving your standing with email service providers. This guide will walk through the essential steps to turn your email reputation around and boost deliverability.
Understanding email and domain reputation
Before diving into solutions, it's crucial to understand what email and domain reputation actually mean. Email reputation is the score an Internet Service Provider (ISP) assigns to your sending IP address and domain, indicating how trustworthy your emails are. A poor reputation means your emails are likely to land in the spam folder or be blocked entirely, while a good reputation ensures they reach the inbox.
Domain reputation is tied to your domain name (e.g., example.com) and is influenced by user engagement and spam complaints over time. IP reputation is associated with the IP address from which your emails originate. While they are distinct, both significantly impact email deliverability. A common misconception is that fixing one automatically fixes the other, but a holistic approach is needed.
When your domain reputation is bad, it signals to ISPs that your sending practices are problematic. This can result from high spam complaints, sending to invalid addresses, or being caught in spam traps. Identifying the root cause is the first step toward recovery. Often, an abrupt drop in reputation, like one seen around a specific month, points to a change in sending behavior or list quality around that time.
It's a mistake to try and fix reputation by focusing solely on the reputation score itself. Instead, the focus should be on resolving the underlying issues that caused the decline. By addressing the core problems, your reputation will naturally improve over time. This includes taking aggressive action if emails are consistently going to spam, as continuing to send such mail only exacerbates the problem and makes recovery harder.
Foundational steps for recovery
The cornerstone of improving your email and domain reputation is rigorous list hygiene. A clean, engaged list is paramount. This means regularly removing inactive or invalid email addresses, identifying and eliminating spam traps, and ensuring all subscribers have explicitly opted in. For new subscribers, implementing double opt-in is a highly effective way to verify addresses and reduce bounce rates.
When facing a severely damaged reputation, consider a temporary halt or drastic reduction in marketing sends. While this might seem counter-intuitive to revenue goals, sending emails that consistently land in spam only deepens the hole. Focus instead on transactional emails, which typically have higher engagement and can help rebuild a baseline of trust. This strategic pause allows you to clean your list thoroughly and reset sending patterns.
Aggressive pruning for recovery
If your mail is primarily going to spam, continuing to send at high volumes is detrimental. Stop or drastically reduce sends of any content that consistently lands in the spam folder. Your deliverability won't improve by continuing bad practices, even if it has generated some revenue in the past. It's time to accept those as sunk costs to protect your future email program.
Once your list is clean, implement a cautious re-engagement strategy. This means segmenting your audience and sending to your most engaged subscribers first. Monitor their reactions closely, paying attention to opens, clicks, and especially spam complaints. Gradually expand your sending volume and audience as your metrics improve. This slow and steady approach is vital for long-term reputation building and avoiding future blocklists.
Technical authentication and infrastructure
Proper email authentication is non-negotiable for improving your email and domain reputation. SPF, DKIM, and DMARC records tell receiving mail servers that your emails are legitimate and haven't been tampered with. These are critical for establishing trust and ensuring your emails pass through spam filters.
For organizations sending high volumes, separating your mail streams is highly recommended. This means using different IP addresses and potentially subdomains for transactional emails versus marketing or bulk emails. Transactional emails (e.g., password resets, order confirmations) typically have higher engagement and lower complaint rates, making them valuable for maintaining a positive sending reputation. By isolating them, you protect their deliverability from any issues that might arise with marketing campaigns. I've seen many companies use different providers for transactional emails alone, like Postmark.
Dedicated IP
Control: Your IP reputation is solely dependent on your sending practices.
Volume: Ideal for high-volume senders (hundreds of thousands of emails monthly) who want full control.
Recovery: If reputation is bad, it requires significant effort to clean and rebuild.
Shared IP
Control: Reputation is shared with other senders, potentially affecting yours.
Warm-up: Less individual warm-up required as the IP has an established history.
Volume: Best for lower-volume senders or those just starting out.
Recovery: Switching to a shared IP generally won't fix underlying sending practice issues.
For high-volume senders with a history of poor reputation, sticking with a dedicated IP and focusing on improving your own sending practices is typically the better long-term strategy. You have more control over your reputation and can rebuild it systematically. Switching to a shared IP often won't resolve fundamental sending issues, and you might find your problems persisting or even exacerbated by the actions of other senders on that shared IP.
Content and engagement strategies
Beyond technical configurations, the content of your emails and how your audience engages with them are crucial. ISPs prioritize sending high-quality, relevant emails that recipients actually want to open and click on. If your emails consistently get low engagement, high spam complaints, or are marked as junk, your reputation will suffer, regardless of your authentication setup.
Avoid characteristics commonly associated with spam. This includes excessive use of spam trigger words, overly promotional language, or deceptive subject lines. Ensure your emails provide clear value to the recipient. Always include a clear and easy-to-find unsubscribe link, and honor unsubscribe requests promptly. Failing to do so can lead to higher spam complaints, which are severely detrimental to your reputation.
Monitor your engagement metrics closely. Open rates, click-through rates, and reply rates are strong indicators of how recipients perceive your emails. A decline in these metrics, particularly after an increase in send volume, can signal a problem. Conversely, consistently high engagement sends positive signals to ISPs, helping to rebuild your sender reputation.
Metric
Impact on reputation
Action to improve
Open rate
Low rates signal disinterest or filtering, harming reputation.
Optimize subject lines, preheaders, and sender name.
Click-through rate (CTR)
High rates indicate relevant content, boosting trustworthiness.
Ensure compelling content and clear calls-to-action.
Spam complaint rate
Any complaints severely damage reputation and deliverability.
High rates indicate poor list hygiene, negatively affecting reputation.
Regularly clean lists and use double opt-in.
A long-term commitment to deliverability
Rebuilding email and domain reputation is not an overnight process. It requires consistent effort across multiple areas, from maintaining a pristine email list to ensuring proper technical authentication and delivering highly engaging content. You'll need to focus on the underlying issues that caused the reputation drop, rather than just the reputation score itself.
By implementing these strategies, continuously monitoring your performance, and adjusting your approach based on data, you can steadily improve your standing with ISPs. This will lead to better inbox placement, higher engagement, and ultimately, more successful email campaigns. Recovering your email reputation is a marathon, not a sprint, but the rewards of improved deliverability are well worth the effort.
Views from the trenches
Best practices
Implement stringent list hygiene by regularly removing inactive or invalid addresses to prevent bounces and spam traps.
Utilize email authentication protocols like SPF, DKIM, and DMARC to verify your sending legitimacy and prevent spoofing.
Segment your email lists based on engagement levels, prioritizing sends to your most active subscribers during recovery.
Separate your transactional email streams from marketing emails by using different IP addresses or subdomains.
Focus on sending highly relevant and valuable content that encourages positive engagement from recipients.
Common pitfalls
Continuing to send high volumes of email when deliverability is poor, further damaging your reputation.
Ignoring email authentication settings, leaving your domain vulnerable to impersonation and filtering.
Failing to clean your email list, leading to high bounce rates and increased spam trap hits.
Mixing transactional and marketing emails on the same IP, which can jeopardize critical communications.
Not monitoring engagement metrics or acting on low open rates and high complaint rates.
Expert tips
Consider a temporary pause on marketing sends if your reputation is severely damaged, to facilitate a focused recovery.
Leverage email warm-up strategies when restarting or increasing sending volume, even on established IPs.
Regularly check for inclusion on common email blocklists (or blacklists) to quickly address any issues.
Analyze Postmaster Tools data from Google and Yahoo to gain insights into your domain's reputation and performance.
Focus on the underlying reasons for poor deliverability; fixing these will naturally improve your reputation.
Expert view
Expert from Email Geeks says IP reputation and domain reputation are distinct factors.
2024-05-31 - Email Geeks
Expert view
Expert from Email Geeks says switching to a shared IP will not improve deliverability until fundamental sending practices are fixed, and dedicated IPs are preferable for high-volume senders.
