How to conduct an in-depth email deliverability and reputation audit for a business?
Matthew Whittaker
Co-founder & CTO, Suped
Published 19 Apr 2025
Updated 19 Aug 2025
7 min read
Ensuring your emails reach the inbox is fundamental to any successful digital strategy. Even a slight dip in email deliverability can lead to significant losses in engagement, sales, and overall communication effectiveness. An in-depth email deliverability and reputation audit is not just a reactive measure, it's a proactive health check for your entire email ecosystem. It allows you to uncover hidden issues, optimize your sending practices, and ultimately safeguard your sender reputation.
This comprehensive process goes beyond surface-level checks. It involves a deep dive into technical configurations, sending practices, content quality, and engagement metrics. By systematically analyzing these areas, you can identify the root causes of deliverability challenges and implement effective solutions to improve your inbox placement rates.
For any business relying on email communication, understanding and actively managing deliverability and sender reputation is non-negotiable. Without a robust audit, you might be unknowingly sending emails directly to the spam folder, missing out on crucial opportunities, and damaging your brand's trustworthiness.
Sender reputation and its impact
Your sender reputation is the collective score internet service providers (ISPs) assign to your sending IP addresses and domains. This score dictates whether your emails land in the inbox, spam folder, or are blocked entirely. A good reputation means ISPs trust your sending practices, while a poor one signals potential spamming behavior.
Several factors contribute to your sender reputation, including bounce rates, spam complaint rates, and engagement metrics like open and click-through rates. High bounce rates indicate an unhealthy email list, while frequent spam complaints tell ISPs that recipients do not want your messages. Low engagement, conversely, suggests recipients aren't finding your emails valuable. Regularly monitoring these metrics is crucial for maintaining a positive sending reputation.
An email deliverability audit helps you gain a comprehensive understanding of your current standing. Key indicators to assess include inbox placement rates across different providers, historical bounce data, and the frequency of spam complaints. For a detailed guide on improving your sender reputation, consider our article on how to improve email IP and domain reputation.
A fundamental part of any email audit is examining your technical setup. This includes verifying that your email authentication protocols—SPF, DKIM, and DMARC—are correctly configured. These records prove that your emails are legitimate and prevent spoofing. Misconfigurations here are common causes of emails landing in spam. For a comprehensive overview, see our simple guide to DMARC, SPF, and DKIM.
Next, you need to check your IP and domain against various blocklists (often called blacklists). Being listed on a major blocklist can severely impact your deliverability. These lists track IPs and domains sending spam or suspicious emails. You can use a blocklist checker to see if your sending infrastructure has been flagged. Our in-depth guide to email blocklists provides more context on how they work.
Key technical areas
SPF record: Verify all legitimate sending IPs and services are authorized. Ensure you haven't exceeded the 10-lookup limit.
DKIM signature: Confirm your outgoing emails are consistently signed and the DNS record is correct.
DMARC policy: Check for proper implementation and alignment with SPF and DKIM. Analyze your DMARC reports for insights into your email stream.
DNS records: Confirm that all relevant DNS records, including MX records, are accurately configured and propagated.
Furthermore, a thorough audit includes examining your mail server logs and reviewing any bounce messages to understand the specific reasons for delivery failures. These technical details often reveal underlying problems that, once fixed, can significantly boost your deliverability. Our expert guide to email deliverability delves into common reasons for email failure and how to address them.
Content and engagement audit
Beyond the technical aspects, the content of your emails and how recipients engage with them play a massive role in deliverability. ISPs analyze email content for spammy characteristics, so a review of your creative strategy is essential. This includes evaluating subject lines, body copy, image-to-text ratio, and the inclusion of potentially problematic links or attachments.
Your email list's health is directly tied to your sender reputation. A high percentage of invalid, inactive, or spam trap addresses can quickly flag your sending domain as suspicious. Regular list hygiene, including removing unengaged subscribers and validating new addresses, is crucial. Spam traps, in particular, are hidden landmines that can instantly damage your reputation. Learn more about them in our guide on what are spam traps.
Engagement metrics are a direct signal to ISPs about the relevance of your emails. Low open rates, click-through rates, or high unsubscribe rates can negatively impact your deliverability. Analyzing these trends helps you refine your segmentation, personalize content, and optimize sending frequency. Experiment with A/B testing different subject lines and call-to-actions to see what resonates best with your audience. For deeper insights, explore our blog on why your email deliverability rate is wrong.
Monitoring and ongoing optimization
An email deliverability and reputation audit isn't a one-time task, it's an ongoing process. Consistent monitoring is essential to catch potential issues early and maintain optimal inbox placement. Utilize various tools to keep a pulse on your sender reputation, blocklist status, and key performance indicators.
Set up alerts for significant changes in your spam complaint rates or if your IP or domain gets listed on a major blocklist. Regularly review DMARC reports to ensure proper authentication and identify any unauthorized sending. Consider our guide on DMARC monitoring for more information. This proactive approach allows for quick remediation of issues before they escalate.
Before the audit
High bounce rates, frequent spam folder delivery, and low open rates are common symptoms of underlying deliverability issues. Without an audit, these problems often go unaddressed, leading to missed opportunities and a damaged sender reputation.
Unknown issues: You may not be aware of blocklist listings or authentication errors.
Ineffective campaigns: Even great content won't matter if it never reaches the inbox.
Lost revenue: Poor deliverability directly impacts the ROI of email marketing efforts.
After the audit
An audit provides a clear roadmap for improvement, enabling you to address specific technical and content-related issues. This leads to better inbox placement, higher engagement, and ultimately, a stronger email program.
Identified issues: Clear understanding of technical misconfigurations, list hygiene problems, and content flags.
Optimized performance: Improved inbox placement and higher engagement metrics.
Enhanced reputation: A healthier sender score and stronger brand trust with ISPs.
Regularly testing your email deliverability using seed list providers can give you real-time insights into where your emails are landing across various mailbox providers. These tests help you quickly detect if recent changes to your sending practices or content have impacted your inbox placement. Consistent optimization based on these insights is key to long-term email success.
Views from the trenches
Best practices
Always maintain clean email lists to minimize bounce rates and avoid spam traps.
Consistently monitor your sender reputation using tools like Google Postmaster.
Ensure SPF, DKIM, and DMARC records are correctly set up and aligned.
Segment your audience and personalize content to boost engagement metrics.
Implement feedback loops to manage spam complaints promptly.
Common pitfalls
Ignoring DMARC reports, missing critical insights into email authentication failures.
Sending emails to old or unverified lists, leading to high bounce rates and spam trap hits.
Over-relying on a single metric instead of a holistic view of deliverability.
Failing to warm up new IPs or domains before sending large volumes of email.
Not regularly checking for blacklisting, which can silently kill deliverability.
Expert tips
Use seed list testing regularly to identify inbox placement issues across providers.
Focus on domain reputation over IP reputation for long-term deliverability health.
Engage with your IT department to ensure proper technical configurations and server health.
Implement a clear unsubscribe process to reduce spam complaints and improve user experience.
Analyze engagement patterns to identify disengaged subscribers and suppress them.
Marketer view
Marketer from Email Geeks says that for deliverability, they primarily use MxToolbox and Litmus. They also suggested connecting with the IT department for assistance.
2025-04-15 - Email Geeks
Expert view
Expert from Email Geeks says an in-depth audit typically requires paying consultants because it involves examining practices and procedures in addition to technical data. There isn't a simple 'magic score' number.
2025-04-16 - Email Geeks
Strengthening your email foundation
Conducting an in-depth email deliverability and reputation audit is a multi-faceted process that requires attention to detail across technical, content, and engagement aspects. By systematically evaluating each area, businesses can gain a clear understanding of their email program's health and identify specific areas for improvement. This proactive approach not only resolves existing issues but also builds a resilient email sending infrastructure that ensures consistent inbox placement.
The insights gained from an audit empower you to make data-driven decisions, optimize your email strategy, and protect your brand's reputation. Remember, consistent monitoring and adaptation are key to navigating the ever-evolving landscape of email deliverability.
Microsoft SNDS. These provide valuable insights into your domain and IP reputation directly from major mailbox providers. Additionally, our guide on how to accurately test and measure email deliverability offers practical steps.
