What are the best tools for tracking email deliverability outside of an ESP?

Key findings

• Diverse Needs: The most effective deliverability strategies often involve a combination of free and paid tools, tailored to specific goals like inbox placement testing, authentication validation, or spam trap monitoring.
• Core Metrics: Beyond basic open and click rates, key metrics to track include bounce rates (hard and soft), blocklist status, and spam complaint rates, broken down by domain group.
• Free Resources: Tools like Google Postmaster Tools and Microsoft's SNDS provide invaluable, free data on your sender reputation and email performance with major ISPs.
• Data-Driven Decisions: Analyzing your own email data (e.g., bounce logs, open rates by domain) is fundamental for diagnosing deliverability issues, complementing the insights gained from third-party tools.
• Authentication Monitoring: Dedicated tools for DMARC reporting and analysis are critical for ensuring your emails are properly authenticated and preventing spoofing.

Key considerations

• Budget vs. Features: Assess whether a free tool provides sufficient insight or if a paid solution is necessary for the depth of data and features you require. Consider if the investment justifies the potential improvement in inbox placement.
• Integration: While looking outside your ESP, consider how easily a new tool's insights can be integrated into your existing workflow or data analysis process.
• Gmail API Changes: Be aware of how changes in ISP APIs (like Gmail's) might affect the reliability of panel-based deliverability monitoring and adapt your strategy accordingly.
• Customization: The ability to customize dashboards and reports (e.g., by domain group) within your chosen tool or ESP can significantly enhance your ability to diagnose and address specific issues.

Key opinions

• Valuable Supplement: Many marketers find significant value in third-party tools that supplement their ESP's built-in analytics, especially for deeper diagnostics.
• Preference for Established Names: Well-known tools like 250ok and Return Path are frequently mentioned due to their comprehensive features for deliverability monitoring.
• Beyond Tools: Successful deliverability isn't solely about tools; it also involves analyzing internal data and understanding sending practices thoroughly.
• Importance of Free Tools: Marketers highly recommend starting with free tools like Google Postmaster Tools and Microsoft's SNDS for fundamental insights into domain reputation and email performance.

Key considerations

• In-house Data: Marketers should always cross-reference external tool data with their own ESP's reports, especially regarding bounces and blocklist activity.
• API Limitations: Understand that changes in ISP APIs (like Gmail's) can impact the accuracy of panel-based deliverability monitoring, requiring adaptation in how data is interpreted.
• Custom Dashboards: The ability to create custom dashboards for deliverability by domain group within an ESP or a third-party tool is highly valued for its diagnostic capabilities.
• Long-Term View: Consistently monitoring deliverability trends over time, rather than focusing on single snapshots, is key to identifying and addressing underlying issues. Tools that offer historical data are beneficial.

Key opinions

• Beyond Basic Metrics: Experts stress that while ESPs offer basic data, external tools provide crucial insights into how ISPs perceive your email stream, which directly impacts inbox placement.
• Data Integration: The most effective deliverability management involves integrating data from various sources, including ESP reports, Postmaster tools, and third-party monitoring services.
• Proactive Monitoring: Regularly checking domain and IP reputation across various blacklists and blocklists is vital for early detection of issues.
• Authentication Health: Ensuring proper SPF, DKIM, and DMARC configuration and monitoring their performance is a non-negotiable aspect of good deliverability, often requiring specialized tools.

Key considerations

• Correlation, Not Causation: Experts advise that while tools provide data, correlating different data points (e.g., sudden drop in opens with a new blocklist entry) is where true diagnostic value lies.
• Long-Term Trends: Focus on long-term trends rather than daily fluctuations. A sudden drop in deliverability might be a red flag, but consistent downward trends indicate deeper problems requiring strategic changes.
• Spam Trap Monitoring: Leverage tools that include spam trap detection as hitting these can severely damage sender reputation.
• Understanding ISP Behavior: The insights from tools should be used to understand specific ISP filtering mechanisms, as these vary and impact deliverability uniquely.

Key findings

• Authentication is Key: Documentation from major ISPs (e.g., Google, Microsoft) stresses that properly configured SPF, DKIM, and DMARC records are fundamental for email authentication and spam prevention.
• Reputation Management: Official guides often detail how sender reputation is built and maintained, emphasizing factors like low spam complaint rates, valid recipient lists, and consistent sending volume.
• Feedback Loops: Documentation encourages senders to sign up for ISP feedback loops to receive reports on spam complaints, allowing for prompt list hygiene.
• Content Guidelines: Many resources provide specific content and formatting guidelines to avoid triggering spam filters, advising against suspicious links, excessive images, or spammy keywords.

Key considerations

• Adherence to Standards: It is crucial to adhere to published internet standards (RFCs) for email protocols, as deviations can lead to delivery failures. This foundational compliance is often detailed in documentation.
• Monitoring Tools Provided: ISPs frequently offer their own Postmaster tools (e.g., Google Postmaster Tools, Outlook.com Smart Network Data Services) that should be utilized for direct insight into how your mail is performing with them.
• Policy Enforcement: Understand that ISPs enforce strict policies against unsolicited email, and documentation outlines the consequences of violating these policies, including blacklisting.
• List Management: The importance of obtaining explicit consent for email sending and providing easy unsubscribe options is consistently emphasized in deliverability documentation to maintain a healthy sending reputation.