Who are the best deliverability experts and tools for auditing email performance?
Michael Ko
Co-founder & CEO, Suped
Published 17 Apr 2025
Updated 19 Aug 2025
8 min read
Maintaining strong email deliverability is crucial for any business relying on email communication. Whether you're sending transactional alerts, marketing campaigns, or critical business communications, emails need to reach the inbox consistently. When messages start landing in spam folders or aren't delivered at all, it can significantly impact operations and revenue.
I've seen firsthand how quickly deliverability can decline without proper oversight. It's not just about sending emails, but ensuring they are seen and acted upon. Often, identifying the root cause of deliverability issues requires a deep dive into technical configurations, sending practices, and reputation metrics that go beyond basic email service provider (ESP) reports. This is where the expertise of a specialized consultant or advanced auditing tools become invaluable.
The role of email deliverability experts
Email deliverability experts bring specialized knowledge to diagnose and resolve complex email sending issues. They can review your entire email program, from infrastructure setup to content strategies, and pinpoint areas that are hindering inbox placement. Many businesses find that while they understand the basics of email, the nuances of mailbox provider algorithms and global spam filtering require a dedicated specialist.
These experts often have direct relationships with major internet service providers (ISPs) like Google and Yahoo, giving them insights into policy changes and best practices that aren't widely publicized. They can guide you through the process of improving your sender reputation, handling blocklist (or blacklist) issues, and ensuring your email authentication protocols are correctly implemented. For example, a good consultant can help you interpret DMARC reports from Google and Yahoo to identify specific issues.
Hiring an expert is particularly valuable when you have multiple email sending platforms or are experiencing persistent deliverability problems that impact critical communications, like transactional emails. They can offer an objective, external perspective on your setup and help you develop a comprehensive strategy for long-term email health. A recommended deliverability expert, Mickey Chandler, offers consulting services through Whizardries.
While an expert can kickstart your journey to better inbox placement, the initial step often involves contacting your ESP's deliverability team. They have deep visibility into your sending data and infrastructure within their system, which can provide a valuable starting point for diagnosis. Afterwards, an independent expert can provide a broader audit beyond the ESP's specific environment, especially if you're using multiple sending services.
Essential tools for auditing email performance
Beyond human expertise, a range of tools exists to help you audit and monitor your email performance. These tools provide critical data that ESPs often don't expose in their standard dashboards, such as inbox placement rates across different mailbox providers, blocklist (or blacklist) status, and detailed authentication insights. Using the email deliverability tester can be a great first step.
One category of tools focuses on pre-send testing, allowing you to check how your email will perform before you send it to your entire list. These often include spam filter tests, rendering previews, and authentication checks. They can flag issues like broken links, poor HTML, or missing authentication records (like SPF, DKIM, and DMARC) that could lead to deliverability problems. Understanding popular email deliverability testing tools can empower your team.
Another crucial set of tools provides ongoing monitoring. These services keep an eye on your sending IPs and domains, alerting you if they appear on any major email blocklists. They also often track your sender reputation metrics across various ISPs, giving you an early warning sign if your deliverability is starting to dip. For example, some tools specialize in blocklist monitoring, which is essential for proactive management.
For comprehensive insights, you might also consider platforms that integrate DMARC monitoring. DMARC reports provide aggregated feedback on your email authentication status and can highlight issues like spoofing attempts or misconfigured sending sources. Combining these tools with regular manual checks forms a robust auditing strategy, helping you to track all-round email deliverability.
Key areas for an email deliverability audit
An effective email performance audit encompasses several key areas. It's not just about checking if an email arrived, but understanding the entire journey and the factors influencing it. I typically break down an audit into reputation, technical configuration, and content.
First, sender reputation is paramount. This involves analyzing both your IP and domain reputation. Key indicators include spam complaint rates, bounce rates, interaction rates (opens and clicks), and direct feedback loop data. If your IPs or domains are listed on major blocklists (or blacklists), it will severely impact your deliverability. You can check your blocklist status using a blocklist checker, which can tell you what happens when your domain is on an email blacklist. This also includes monitoring for spam trap hits, which are strong indicators of poor list hygiene. A comprehensive guide on email deliverability audits provides deeper insights into these checks.
Second, technical configurations are critical. This means verifying your DNS records for SPF, DKIM, and DMARC. Misconfigurations here are common causes of delivery failures. For instance, an incorrect DMARC record or a missing DKIM signature can lead to emails being rejected or sent to spam. Reverse DNS (rDNS) records and proper IP warm-up procedures also fall under this category. Auditing your setup can improve IP and domain reputation.
Finally, the audit should extend to your email content and list management practices. This includes checking for spammy keywords, excessive links, large image-to-text ratios, and overall message relevance. List hygiene is also paramount. Regularly cleaning your email lists to remove inactive subscribers, hard bounces, and known spam traps will significantly boost your deliverability. Identifying and troubleshooting why your emails fail is a continuous process.
Ongoing monitoring and maintenance
An email deliverability audit isn't a one-time fix. It's an ongoing process that requires continuous monitoring and adaptation. Mailbox providers frequently update their filtering algorithms, and your sender reputation can fluctuate based on your sending volume, recipient engagement, and even external factors like phishing attacks that target your domain.
Establishing a routine for monitoring your deliverability metrics is essential. This includes regularly checking Google Postmaster Tools, Yahoo Sender Hub, and any third-party deliverability monitoring services you use. Look for sudden drops in inbox placement, increases in spam complaints, or new blocklist (blacklist) listings. Proactive identification of these issues allows for swift action before they escalate into major problems.
Furthermore, staying informed about industry best practices and upcoming changes from major mailbox providers is crucial. For example, recent announcements from Microsoft and Google regarding new sender requirements highlight the need for continuous vigilance. Regularly review your email sending practices, update your authentication records as needed, and refine your content based on engagement metrics to ensure optimal deliverability.
While tools offer data, deliverability experts provide the strategic guidance to interpret that data and implement effective solutions. They can help you troubleshoot specific issues, like how to troubleshoot customer deliverability issues, and build a resilient email program. Their insights are invaluable for navigating the complex landscape of email security and deliverability.
Views from the trenches
Best practices
Actively monitor your DMARC reports to spot potential authentication issues or unauthorized sending activity from your domain.
Regularly clean your email lists to remove inactive subscribers, hard bounces, and known spam trap addresses to maintain high engagement.
Implement a consistent IP warm-up strategy when using new IPs or significantly increasing sending volume to build a positive sender reputation.
Ensure all your sending domains have properly configured SPF, DKIM, and DMARC records to authenticate your emails effectively.
Common pitfalls
Ignoring early warning signs from deliverability monitoring tools, leading to compounded issues and harder recovery.
Failing to adapt email content and sending frequency based on recipient engagement, which can lead to increased spam complaints.
Not having a clear process for handling bounced emails and unsubscribes, causing continued mailing to problematic addresses.
Relying solely on ESP reports without cross-referencing with independent deliverability tools for a complete picture.
Expert tips
Use dedicated IPs for transactional emails to separate their reputation from marketing sends, ensuring critical messages reach the inbox.
Segment your audience and tailor content to improve engagement, as positive interactions are a strong signal to mailbox providers.
Leverage Google Postmaster Tools and Yahoo Sender Hub for direct insights into your domain's reputation with these major providers.
Consider engaging a third-party deliverability consultant for complex issues or to get an unbiased audit of your email program.
Marketer view
Marketer from Email Geeks says a deliverability expert can certainly help set up systems, but ongoing monitoring with a third-party tool is also crucial for alerting.
2024-04-03 - Email Geeks
Marketer view
Marketer from Email Geeks says that while there are many good experts, contacting the ESP's deliverability team should be a first step, as they have access to more detailed data.
2024-04-02 - Email Geeks
Ensuring your emails arrive
Auditing your email performance and leveraging expert guidance are indispensable for maintaining high deliverability. Whether you opt for a dedicated deliverability consultant, invest in advanced monitoring tools, or utilize a combination of both, the goal remains the same: ensuring your emails consistently reach the inbox.
By understanding the importance of sender reputation, diligently configuring technical standards like SPF, DKIM, and DMARC, and maintaining a clean email list, you can significantly improve your email program's effectiveness. Proactive monitoring and a willingness to adapt to the ever-evolving landscape of email security will ensure your messages continue to land where they belong.
Google and 
Yahoo, giving them insights into policy changes and best practices that aren't widely publicized. They can guide you through the process of improving your sender reputation, handling blocklist (or blacklist) issues, and ensuring your email authentication protocols are correctly implemented. For example, a good consultant can help you interpret DMARC reports from Google and Yahoo to identify specific issues.
Microsoft and Google regarding new sender requirements highlight the need for continuous vigilance. Regularly review your email sending practices, update your authentication records as needed, and refine your content based on engagement metrics to ensure optimal deliverability.
