Summary
Measuring email deliverability outside of campaign metrics involves a multi-faceted approach combining various tools and methods. While seed list testing (like GlockApps) can provide initial insights, their accuracy is limited due to sample size and the snapshot-in-time nature of the data. A more comprehensive strategy includes monitoring sender reputation through Google Postmaster Tools, Sender Score, and Microsoft's Sender Support. Actively tracking blocklists using tools like MultiRBL and Spamhaus is also essential. Implementing and maintaining SPF, DKIM, and DMARC are critical for authentication and preventing spoofing. Setting up feedback loops (FBLs) offers valuable insight into recipient engagement and spam complaints. Warming up new IP addresses helps build a positive reputation. Expert opinions emphasize that deliverability problems rarely stem from a single issue but rather a confluence of factors, necessitating a holistic diagnostic approach and that deliverability is a continuous process. Therefore, a combination of tools and proactive monitoring is key to effective deliverability management.
Key findings
- Seed List Limitations: Seed lists offer an incomplete and time-sensitive view of deliverability, and can be inaccurate or skewed by sender interaction.
- Sender Reputation Monitoring: Tools like Google Postmaster Tools and Sender Score provide crucial insights into how mailbox providers perceive your sending reputation.
- Blocklist Monitoring: Actively monitoring blocklists using tools like MultiRBL and Spamhaus helps identify potential deliverability issues early on.
- Email Authentication: Implementing SPF, DKIM, and DMARC is crucial for authenticating your emails and preventing spoofing.
- Feedback Loops: Feedback loops (FBLs) provide valuable information on recipient complaints and spam reports.
- IP Warm-up: Gradually warming up new IP addresses helps build a positive sender reputation with ISPs.
- Holistic Approach: Deliverability problems are usually caused by a confluence of factors rather than a single root cause, and a combination of tools and proactive monitoring is important.
Key considerations
- Continuous Process: Deliverability management is an ongoing process that requires continuous monitoring and adjustments.
- Tool Limitations: No single tool can provide a complete picture of deliverability; a combination of methods is necessary.
- Holistic Diagnosis: When diagnosing deliverability problems, consider a broad range of potential factors rather than focusing on a single issue.
- Proactive vs. Reactive: Focus on proactive measures (authentication, reputation monitoring) to prevent deliverability problems rather than solely reacting to issues as they arise.
- Platform Specifics: Be aware that some tools are platform-specific (e.g., Google Postmaster Tools for Gmail) and may not provide a complete view of your overall deliverability.
What email marketers say
13 marketer opinions
Measuring email deliverability beyond campaign metrics involves a multi-faceted approach. Seed list testing, like GlockApps, can provide insights into inbox placement but may have limitations due to sample size. Monitoring tools like Google Postmaster Tools, Sender Score, and blocklist monitors help gauge sender reputation and identify deliverability issues. Setting up and monitoring feedback loops is crucial for understanding recipient reactions. Ensuring proper SPF, DKIM, and DMARC authentication is essential, and warming up IP addresses helps build a positive reputation with ISPs. Consider using a combination of methods, as individual tools have limitations.
Key opinions
- Seed List Testing: Tools like GlockApps offer a benchmark, but their seed sample size can be limiting, especially for Gmail.
- Sender Reputation: Monitoring sender reputation via Google Postmaster Tools and Sender Score provides insights into how mailbox providers view your sending practices.
- Blocklist Monitoring: Blocklist monitoring alerts you when your IP or domain is listed, allowing for prompt action.
- Authentication: Properly configured SPF, DKIM, and DMARC records are critical for email authentication and improving deliverability.
- Feedback Loops: Feedback loops (FBLs) provide valuable insights into recipient spam complaints, enabling list hygiene.
- IP Warm-up: Warming up IP addresses, especially new ones, helps build a positive sender reputation by gradually increasing sending volume.
- MultiRBL: MultiRBL can check IP addresses and domains against multiple RBLs (Real-time Blackhole Lists) at once to identify if you're being blocked by any of them.
Key considerations
- Holistic Approach: A single tool or method is insufficient; a holistic approach combining multiple strategies is necessary for comprehensive deliverability monitoring.
- Seed Accuracy: Seed lists are only a snapshot in time and do not reflect the broader sending and recipient engagement dynamic. Deliverability is a continuous process so more active monitoring is important.
- Gmail Focus: Gmail deliverability requires specific attention due to its unique handling of email and the limited usefulness of seed tests compared to campaign metrics.
- Personalized Seeds: Personal seeds can be skewed by user interaction, influencing ISP perceptions. It is better to use seeds that don't get interacted with.
- Proactive Monitoring: Proactive monitoring of external reputation services will help identify deliverability problems before they are noticed on campaign metrics.
Marketer view
Expert from Email Geeks recommends that senders develop their own seeds in addition to using tools like Glock. They have observed Glock and similar services reporting inaccurate issues, and advise against relying solely on third-party apps.
30 Nov 2022 - Email Geeks
Marketer view
Email marketer from Quora shares the importance of inbox placement tests with tools like GlockApps, Litmus, or Email on Acid, which allows you to see where emails land (inbox, spam, or missing) across different providers.
5 May 2025 - Quora
What the experts say
4 expert opinions
Measuring email deliverability beyond campaign metrics and tools like GlockApps requires a comprehensive approach. Seed lists offer a limited and potentially inaccurate snapshot of deliverability. Actively monitoring IPs, domains via external reputation services, and blocklists helps proactively identify issues. Setting up and monitoring feedback loops is critical for understanding recipient engagement and reactions, and that deliverability issues typically stem from multiple factors, not a single cause.
Key opinions
- Seed List Limitations: Seed lists provide an incomplete and time-sensitive view of deliverability, making them insufficient as a standalone measure.
- Proactive Monitoring: Monitoring IPs and domains with external reputation services and blocklists enables early detection of deliverability issues.
- Feedback Loops: Feedback loops provide crucial insights into how recipients are reacting to your mail, indicating potential problems.
- Confluence of Issues: Deliverability problems typically arise from a combination of factors, necessitating a holistic diagnostic approach.
Key considerations
- Continuous Process: Deliverability is an ongoing process that requires continuous monitoring and adjustments, not a one-time fix.
- Holistic Diagnosis: When facing deliverability issues, consider a broad range of potential causes rather than focusing on a single factor.
- Actionable Insights: Reputation services and feedback loops provide actionable information for addressing deliverability problems.
- Active Management: Relying solely on tools without active management and interpretation of the data can be ineffective.
Expert view
Expert from Word to the Wise explains that deliverability problems are rarely caused by one specific issue, but rather a confluence of issues, requiring a holistic approach to diagnosis.
4 Feb 2024 - Word to the Wise
Expert view
Expert from Spam Resource explains that monitoring your IPs and Domains with external reputation services and blocklists will help proactively identify deliverability problems.
26 Apr 2023 - Spam Resource
What the documentation says
6 technical articles
Measuring email deliverability involves utilizing various tools and authentication methods. Google Postmaster Tools provides insights into sending reputation and spam rates specifically for Gmail. Microsoft's Sender Support portal helps troubleshoot deliverability issues with Outlook.com and Hotmail. Spamhaus offers a Blocklist Removal Center to check for IP listing. Implementing SPF, DKIM, and DMARC is crucial for email authentication, preventing spoofing, and establishing policies for handling authentication failures. These combined methods provide a comprehensive approach to monitoring and maintaining email deliverability.
Key findings
- Google Postmaster Tools: Provides specific deliverability data for Gmail, including reputation and spam rates.
- Microsoft Sender Support: Offers resources for troubleshooting deliverability issues when sending to Microsoft services.
- Spamhaus Blocklist: Allows checking for IP listings on Spamhaus blocklists and provides removal procedures.
- SPF: Prevents email spoofing by allowing domain owners to specify authorized mail servers.
- DKIM: Ensures message integrity and sender authentication through digital signatures.
- DMARC: Builds on SPF and DKIM to define policies for handling authentication failures and provides reporting mechanisms.
Key considerations
- Platform Specifics: Google Postmaster Tools is specific to Gmail; Microsoft Sender Support targets Microsoft services.
- Proactive Authentication: Implementing SPF, DKIM, and DMARC is a proactive measure to improve deliverability and prevent abuse.
- Blocklist Monitoring: Regularly checking blocklists is essential for identifying and addressing deliverability issues.
- Combined Approach: A combination of monitoring tools and authentication methods provides a comprehensive view of email deliverability.
Technical article
Documentation from DKIM details DomainKeys Identified Mail (DKIM), an email authentication system that uses digital signatures to verify the sender and ensure the message hasn't been altered during transit.
27 Sep 2021 - DKIM
Technical article
Documentation from Microsoft describes the Sender Support portal, which provides information and tools to help senders troubleshoot deliverability issues when sending email to Outlook.com, Hotmail, and other Microsoft services.
26 Dec 2022 - Microsoft
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