Summary
Understanding and effectively using email sender reputation scores, particularly for those with lower sending volumes, can be challenging. Many factors contribute to these scores, which are dynamic and can fluctuate rapidly. For low-volume senders, establishing a stable reputation can be more difficult due to the limited data available to Internet Service Providers (ISPs).
Key findings
- Low Volume Challenges: Some reputation tools, like Google Postmaster Tools and SNDS, require a certain email volume to provide meaningful data, making them less useful for very low-volume senders.
- Rapid Fluctuation: Sender scores can change dramatically in a short period, especially for new or low-volume IP addresses, reflecting quick reputation shifts. This is particularly relevant during IP warming.
- Multiple Sources: No single reputation score or monitoring tool provides a complete picture, as each uses different data pools and methodologies. It's essential to consult various sources (e.g., SenderScore, Talos Intelligence, Microsoft SNDS).
- Proxy Measures: For low-volume senders, blocklist (or blacklist) presence and spam trap hits can serve as useful proxy measures for reputation, even when direct scores are unavailable or unreliable.
Key considerations
- Holistic View: Focus on a combination of metrics rather than obsessing over a single sender score. Consider bounce rates, complaint rates, and engagement data, alongside any available reputation scores. More factors are discussed in this guide on how SenderScore works.
- Gradual Volume Increase: To build a strong reputation, especially for new IPs or domains, gradually increase your sending volume over time. Sudden spikes can negatively impact your standing with ISPs.
- Content Quality: Ensure your email content is relevant, properly formatted, and avoids characteristics commonly associated with spam to prevent negative signals to ISPs and improve your overall reputation.
- List Hygiene: Regularly clean your email lists to remove inactive or invalid addresses, reducing bounces and spam trap hits, which are critical for maintaining a healthy sender reputation.
What email marketers say
Email marketers often find sender reputation scores to be a source of confusion and anxiety. While they acknowledge the importance of these scores, they also grapple with their abstract nature, lack of transparency, and the specific challenges faced by senders with low email volumes. There's a strong sentiment that focusing too heavily on a single score can be misleading, advocating for a broader view of deliverability metrics.
Key opinions
- Score Volatility: Marketers observe that sender scores can swing wildly, sometimes improving significantly in a short period, especially for newly warmed IP addresses. This rapid change can be surprising and often leads to over-excitement or undue concern.
- Low Volume Blind Spots: Tools like Google Postmaster Tools are less effective for low-volume senders, as they often require higher sending thresholds to generate actionable data. This leaves small businesses with fewer direct insights into their reputation.
- Need for Transparency: There's a desire for greater transparency from reputation providers regarding the data sources and weighting used to calculate scores, as the current opacity makes interpretation difficult.
- Alternative Metrics: Marketers often rely on blacklists (or blocklists) and spam trap hits as practical indicators of reputation, viewing them as decent proxies when other score data is sparse or unhelpful, as discussed in guides on email blocklists.
Key considerations
- Don't Overemphasize Single Scores: It's advised not to create unnecessary alarm for clients based on a single score, as the scores are just one part of the overall deliverability picture.
- Multi-Tool Approach: Investigating multiple reputation sources like SenderScore and Talos, even if they show discrepancies, provides a more comprehensive understanding of your sending health, helping you monitor your domain reputation.
- Focus on Actionable Data: Shift focus from abstract scores to tangible email performance indicators, such as inbox placement rates, open rates, and complaint feedback loops, to truly understand deliverability.
- Continuous Monitoring: Regularly monitor your sending practices and reputation metrics across all relevant platforms to quickly identify and address any issues, as advised by email deliverability specialists.
Marketer view
An Email Geeks marketer noted checking IP addresses that returned a 'not enough email' message. They found it odd that the score was in single digits, but quickly realized this indicated a lack of sending history rather than poor reputation, as a client's score jumped from 7 to 85 quickly once volume picked up.
Marketer view
An Email Geeks marketer realized that overemphasizing a client's SenderScore can cause unnecessary anxiety. They stated a preference to focus on metrics from Cisco Talos instead, which they perceived to be more robust. This suggests a shift in how some marketers view the importance of different reputation metrics.
What the experts say
Email deliverability experts consistently emphasize that no single reputation score provides a definitive answer to email deliverability. They highlight the diverse and often opaque nature of how ISPs and reputation services gather and weigh data. For low-volume senders, this complexity is compounded, requiring a more nuanced approach to monitoring and strategy.
Key opinions
- No Single Source: Experts agree that relying on one reputation source is insufficient because each uses different data and processing methods. A comprehensive view requires consulting multiple tools.
- ISP Data Divergence: Mailbox providers are increasingly diverging in their filtering methods, meaning what works for one ISP might not work for another. This makes consistent deliverability a moving target.
- Talos Data Pool: Cisco Talos is often cited as having a significantly larger data pool compared to other services, potentially offering a more robust reputation assessment.
- Low Volume Challenges: Low-volume senders face unique difficulties in establishing and maintaining reputation due to the limited data available for ISPs to assess them accurately.
Key considerations
- Diversify Monitoring Tools: It is strongly recommended to look at multiple sources such as Talos, MyNetWatchman, and Microsoft SNDS, in addition to SenderScore, to gain a balanced perspective on your reputation.
- Focus on Core Practices: Given the lack of transparency in specific reputation algorithms, senders should prioritize universal best practices like maintaining a clean list and encouraging engagement to improve their email domain reputation.
- Understand Score vs. Deliverability: While scores can indicate reputation, focus primarily on actual inbox placement and engagement metrics, as a high score doesn't guarantee delivery and vice-versa. Consistent, healthy sending practices are more indicative of long-term success, as noted by SpamResource.
- Align with ISP Metrics: Recognize that different ISPs weight metrics like complaints, spam trap hits, and engagement differently. Tailor your strategy to common denominators that positively influence multiple providers.
Expert view
An expert from Email Geeks stated that they had never seen a public list of the ISPs that feed data to SenderScore. This highlights the proprietary nature of such data and the limited transparency for senders.
Expert view
An Email Geeks expert advised that no single source serves as 'THE' definitive source for email reputation. They stressed that each reputation tool uses different data points from various places and processes them uniquely, leading to varied results.
What the documentation says
Documentation from various sources highlights that sender reputation is a complex, multi-faceted metric, not a singular score. It's determined by a range of factors that ISPs use to assess a sender's trustworthiness. For effective deliverability, adherence to best practices, consistent sending, and proper authentication are paramount.
Key findings
- Aggregate Metric: Email reputation is not one universal score but rather an aggregate of various metrics ISPs use to gauge reliability, including spam complaints, bounce rates, and user engagement.
- ISP Determination: ISPs assign a reputation score based on sending habits, which directly influences whether emails land in the inbox, spam folder, or are rejected.
- Score Thresholds: Generally, a SenderScore of 80 or higher is considered good, indicating high inbox delivery likelihood, while scores below 70 suggest potential deliverability issues.
- Consistency is Key: Consistent sending frequency and volume are critical for maintaining a stable reputation; erratic patterns can negatively impact perceived trustworthiness.
Key considerations
- Authentication: Implementing proper email authentication protocols like SPF, DKIM, and DMARC is fundamental for establishing and maintaining a positive sender reputation. These protocols signal legitimacy to mailbox providers. Learn more about this in our guide to DMARC, SPF, and DKIM.
- Engagement Matters: Recipient engagement (opens, clicks, replies) positively influences reputation, while negative engagement (spam complaints) harms it. Focus on sending desired content to engaged users.
- Avoid Blocklists: Being listed on a blocklist or blacklist significantly impacts deliverability. Regularly monitor your IP and domain status to avoid or quickly remediate any listings, which you can do with a blocklist checker.
- SenderScore Factors: SenderScore is influenced by data points such as complaint rates, spam trap hits, and invalid addresses. Understanding these inputs helps in targeting areas for improvement, as detailed by the Return Path Sender Score Benchmark Report.
Technical article
A Return Path document defines SenderScore as a numerical measure of an email sender's trustworthiness, ranging from 0 to 100. It clarifies that this score is derived from observed data points like complaint rates, spam trap hits, and invalid addresses across a vast network of mailboxes.
Technical article
A Mailjet guide explains that email reputation is not a single, universally accepted score, but rather an accumulation of various metrics used by ISPs. These metrics are designed to assess a sender's overall reliability and commonly include spam complaints, bounce rates, and user engagement.
Related resources
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