Summary
Email deliverability is a complex topic influenced by numerous factors beyond a single metric like SenderScore. While SenderScore offers a snapshot of your IP address's reputation, it's just one piece of a much larger puzzle. Understanding the full spectrum of elements that impact whether your emails reach the inbox is crucial for successful email marketing and communications.
Key findings
- SenderScore's role: SenderScore, provided by Return Path, is a metric from 0 to 100 that indicates the quality of an IP address's sending reputation over a rolling 30-day period. A high score suggests a good reputation, but it does not guarantee inbox placement.
- Holistic view: Deliverability issues often stem from a combination of factors, not just a low SenderScore. It's important to look at the complete picture of your sending practices.
- IP address impact: For senders using a range of IP addresses, each individual IP's standing on various blacklists (or blocklists) and its SenderScore should be assessed.
- Beyond the score: While SenderScore is a helpful indicator, its correlation with actual inbox placement rates can vary, as detailed in reports like the 2017 Sender Score Benchmark.
Key considerations
- Comprehensive analysis: Do not rely solely on SenderScore for deliverability assessment. Investigate other metrics and factors.
- IP reputation: Ensure all IP addresses associated with your sending, especially dedicated IPs, are regularly checked for blacklist listings and maintaining a good reputation.
- Best practices: Implement and consistently follow email sending best practices, from list hygiene to content quality, to improve overall deliverability and avoid spam folders.
- Proactive monitoring: Actively monitor your sender reputation across various tools, not just SenderScore. You can get your score directly from the SenderScore website.
What email marketers say
Email marketers often find themselves grappling with deliverability issues, even when primary metrics like SenderScore appear healthy. Their perspectives highlight that while a good SenderScore is reassuring, it's frequently insufficient to diagnose or resolve complex inbox placement challenges. Marketers tend to focus on actionable steps they can control, such as content optimization and list hygiene, recognizing that these factors often have a more direct impact on inbox rates than a single reputation score.
Key opinions
- Score is misleading: Many marketers report high SenderScores (e.g., 98) while still experiencing significant spam placement issues, suggesting the score alone doesn't reflect true inboxing.
- Comprehensive approach: It's rare for a single factor to be the root cause of deliverability problems. Marketers advocate for a holistic review of all sending practices.
- Content and subject lines: Optimizing email content and subject lines is a common strategy marketers turn to when facing deliverability challenges, as these directly influence recipient engagement.
- Sender reputation nuances: Sender reputation is influenced by both IP and domain reputation, both of which impact deliverability rates, according to Mailchimp's resources.
Key considerations
- Don't over-rely on one metric: While SenderScore is an indicator, it should not be the sole basis for diagnosing deliverability problems. Look for other signals of poor performance.
- Review IP ranges: If using a range of IPs, ensure all of them have a good standing and aren't listed on any significant blocklists or blacklists.
- Engagement optimization: Focus on improving recipient engagement metrics like open rates and click-through rates. These are strong signals to ISPs, as highlighted by Gleantap's insights on sender score influence.
- Continuous improvement: Adopt a mindset of continuous improvement for your email programs, including content, list management, and authentication to prevent issues like Gmail delivery delays.
Marketer view
Email marketer from Email Geeks indicates that their client's ESP provided initial reputation results, but when they tested it themselves, the SenderScore came back as a high 98. This suggests a potential discrepancy or a limited view of the overall reputation.
Marketer view
Email marketer from Enginemailer explains that many factors, from bad subject lines to IP reputation, email list quality, or even poor timing, can significantly affect email deliverability. This reinforces the idea that a holistic approach is necessary.
What the experts say
Deliverability experts consistently emphasize that while SenderScore is a useful tool, it's just one data point in a complex ecosystem. They caution against using it as the sole indicator of deliverability health, highlighting that various underlying attributes contribute to the score and, more importantly, to actual inbox placement. Their advice centers on a multi-faceted approach that involves deep investigation into sending infrastructure, authentication, and recipient engagement.
Key opinions
- SenderScore as indicator: An expert from Email Geeks (U69M02SDU) advises that a deliverability problem should not be presumed based on SenderScore alone, even if it's low, and that further investigation is required.
- Beyond the score: Another expert from Email Geeks (U8ABMSWDR) agrees that SenderScore is helpful but not the definitive measure, suggesting that a range of attributes contribute to the score and require different approaches to improvement.
- IP reputation's role: Experts stress the critical importance of IP reputation, noting it's a key factor for deliverability and that poor IP health can lead to emails going to spam.
- Authentication impact: Proper email authentication mechanisms like SPF, DKIM, and DMARC are fundamental to ensuring emails reach the inbox, impacting how ISPs trust senders.
Key considerations
- Verify all IPs: For ESPs using multiple IP addresses, ensure each IP is not listed on important Real-time Blackhole Lists (RBLs) and maintains a good SenderScore.
- Understand underlying factors: To improve SenderScore or overall deliverability, identify the specific attributes causing the drop (e.g., spam complaints, bounces, spam trap hits).
- Education is key: For a deeper understanding of email deliverability, consult comprehensive resources and literature, as suggested by an expert in Email Geeks (U69M02SDU).
- Proactive reputation management: Regularly monitor your domain and IP reputation using tools like Google Postmaster Tools, which provide crucial insights into domain reputation and spam rates.
Expert view
Deliverability expert from Email Geeks (U69M02SDU) advises that they would not presume a deliverability problem exists based on a SenderScore alone. This indicates that a single metric is insufficient for a complete diagnosis.
Expert view
Deliverability expert from Word to the Wise emphasizes the importance of good list hygiene. They state that sending to a clean, engaged list is paramount for maintaining a strong sender reputation and avoiding blocklists.
What the documentation says
Official documentation and research often delve into the technical underpinnings of email deliverability, emphasizing how complex algorithms, data points, and protocols interact to determine inbox placement. These resources typically highlight the importance of established standards like SPF, DKIM, and DMARC for authentication, alongside a sender's historical performance, engagement metrics, and compliance with anti-spam policies. SenderScore itself is presented as a quantitative measure derived from many of these factors.
Key findings
- SenderScore calculation: SenderScore is a number between 0 and 100 that reflects the quality of your sender reputation, indicating how mailbox providers view your IP address, according to senderscore.org.
- Authentication standards: SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) are key components that affect email deliverability by verifying sender identity, as noted by Salesforce.
- Factors influencing deliverability: Deliverability is determined by various factors, with sender reputation being paramount, often expressed as a percentage of successful deliveries.
- Data-driven reputation: SenderScore calculates reputation based on a rolling 30-day average, providing a dynamic reflection of sending practices over time.
Key considerations
- Implement authentication: Ensure your domains have properly configured SPF, DKIM, and DMARC records to establish trust with mailbox providers and prevent spoofing. Regularly review your DMARC tags and their meanings.
- Monitor blocklists: Actively monitor common blacklists and blocklists, as inclusion can significantly hinder deliverability, even with a good SenderScore. Understand what happens when your domain is blocklisted.
- Focus on sender reputation: Recognize that deliverability is fundamentally tied to sender reputation, which encompasses IP and domain standing, complaint rates, bounce rates, and engagement.
- Continuous learning: Stay informed about evolving email standards and ISP requirements to maintain optimal deliverability performance, as practices can change.
Technical article
SenderScore.org's documentation defines SenderScore as a numerical value between 0 and 100 that identifies the quality of your sender reputation, indicating how mailbox providers perceive your IP address. It serves as a critical measure of trust.
Technical article
Salesforce's documentation on email deliverability factors states that SPF, DKIM, and DMARC are the key authentication components that directly affect email deliverability. Proper setup of these records is vital for inbox placement.
Related resources
15 resources
Related pages
Email Deliverability Issues: Getting Your Messages to the Inbox in 2025
Why Your Emails Fail: Expert Guide to Improve Email Deliverability [2025]
A simple guide to DMARC, SPF, and DKIM
Why Your Emails Are Going to Spam in 2024 and How to Fix It
An in-depth guide to email blocklists
What causes unexpected IP addresses to appear on Senderscore for dedicated IPs?
How can managing inactive email subscribers improve Gmail deliverability?
Spam traps: what they are and how they work
A practical guide to understanding your email domain reputation
How to safely transition your DMARC policy to quarantine or reject
