Summary
The phenomenon of SNDS showing blocked IPs despite good acceptance rates and engagement is multifaceted. Experts and marketers alike point to the limited and potentially skewed perspective provided by SNDS, which only reflects a subset of Microsoft's complex filtering systems. Possible reasons include: glitches in SNDS reporting, temporary spam complaints or anomalies, Microsoft's A/B testing of filtering rules, delayed data updates, the presence of both good and bad elements in sending infrastructure (e.g., older IPs), issues with content or list hygiene, the algorithm considering factors beyond the normal, and Microsoft’s proprietary algorithms detecting spam traps or unusual sending patterns. Ultimately, SNDS is just one piece of the puzzle, and a holistic approach to monitoring deliverability is essential.
Key findings
- Glitches & Inaccuracies: SNDS may suffer from glitches or inaccuracies in reporting.
- Limited Perspective: SNDS reflects a subset of Microsoft's filtering, not the complete picture.
- Complex Algorithms: Microsoft uses complex and proprietary filtering algorithms.
- Temporary Flags: Blocked IPs can result from temporary issues like spam complaints, or flagging that does not correspond to a long-term problem.
- A/B Testing: Microsoft may be A/B testing different filtering rules that impact SNDS scores.
- Delayed Data: SNDS data is not real-time.
- Infrastructural Issues: Conflicting signals may arise from both good and bad sending elements.
- Content & List Problems: Content or list hygiene issues can trigger specific filters.
- Unexpected Factors: The algorithm might be considering factors beyond content or list hygiene, such as time of day.
Key considerations
- Holistic Approach: Don't rely solely on SNDS; employ multiple monitoring tools.
- Investigate Flags: Investigate blocked status despite good engagement; it can highlight underlying issues.
- Monitor Reputation: Continuously monitor IP reputation and engagement.
- List Hygiene: Maintain rigorous list hygiene practices.
- Content Quality: Ensure high-quality and relevant content.
- Understand Algorithm: Try to understand the underlying filtering algorithms impacting deliverability.
What email marketers say
12 marketer opinions
The consensus among email marketers regarding SNDS showing blocked IPs despite good acceptance rates and engagement points to several possibilities. These include glitches in SNDS reporting, temporary spam complaints or anomalies, Microsoft's A/B testing of filtering rules, delayed data updates in SNDS, the presence of both good and bad elements in sending infrastructure, issues with content or list hygiene, and Microsoft's complex filtering algorithms. It's also suggested that Microsoft's filtering considers factors beyond the normal such as the content or time of day it's being sent. Ultimately, SNDS data should be viewed as one piece of a larger deliverability puzzle, and senders should use multiple monitoring tools to assess their IP reputation and engagement rates.
Key opinions
- SNDS Glitches: Possible glitches or inaccuracies in SNDS reporting can cause discrepancies between blocked status and actual delivery performance.
- Temporary Issues: Temporary spam complaints or anomalies in Microsoft's filters can trigger blocked status, even with good engagement.
- A/B Testing: Microsoft might be A/B testing different filtering rules, flagging IPs for specific segments while performing well overall.
- Delayed Data: SNDS data is not real-time and might reflect past issues that have since been resolved.
- Mixed Infrastructure: Conflicting signals can arise from a sending infrastructure with both good and bad elements, such as older IPs causing problems.
- Content & Hygiene: Problems with content or list hygiene can trigger specific Microsoft filters, leading to a blocked status.
- Unexpected Factors: The filtering considers factors beyond the normal ones, such as content and time of day.
Key considerations
- Holistic View: Relying solely on SNDS data can be misleading; a holistic view of deliverability requires monitoring multiple metrics.
- Investigate Issues: Despite good engagement, a blocked status in SNDS warrants investigation into potential problems with sending practices or infrastructure.
- Monitor Reputation: Continuously monitor IP reputation and engagement rates using various tools to detect and address any deliverability issues promptly.
- List Hygiene: Maintain good list hygiene practices, including regular cleaning and suppression of inactive or problematic addresses.
- Content Quality: Pay close attention to content quality, avoiding spam trigger words and ensuring emails are relevant and engaging.
Marketer view
Email marketer from EmailonAcid Blog shares that SNDS flags could be the result of a recent spike in spam complaints or a sudden shift in sending patterns. Even if engagement remains high, these factors can trigger a temporary block.
24 Mar 2024 - EmailonAcid Blogs
Marketer view
Email marketer from Email Geeks explains that they continued sending volume from IPs flagged as blocked in SNDS because the mail was still being accepted for delivery and others reported similar behaviour.
6 Jul 2021 - Email Geeks
What the experts say
3 expert opinions
Experts attribute SNDS showing blocked IPs with good acceptance rates and engagement to Microsoft's complex and proprietary filtering systems. SNDS color codes aren't definitive delivery indicators, but rather reflect SmartScreen content filter assessments. The data reflects a limited view of Microsoft's internal systems, so an IP may be flagged for hitting spam traps, exhibiting unusual sending patterns, or triggering specific content/list hygiene filters, despite overall good engagement.
Key opinions
- Not Definitive: SNDS color codes are not a definitive indicator of email delivery status, but rather a reflection of SmartScreen content filter assessments.
- Internal Filters: SNDS data is based on Microsoft's internal filtering systems and proprietary algorithms.
- Limited View: SNDS reflects only a small piece of Microsoft's filtering process, and doesn't give a complete picture.
- Spam Traps/Patterns: IPs may be flagged due to hitting spam traps or exhibiting unusual sending patterns.
- Content/Hygiene Issues: Blocked status can also be caused by content or list hygiene problems triggering specific filters.
Key considerations
- Multiple Data Points: Don't rely solely on SNDS data. Consider other metrics and data points for a comprehensive view of deliverability.
- Content and List Analysis: Analyze content and list hygiene to identify potential triggers for Microsoft's filters.
- Understand SNDS Limitations: Recognize the limitations of SNDS as just one component of Microsoft's complex filtering system.
Expert view
Expert from Spamresource.com explains that Microsoft's SNDS data is based on their internal filtering systems. Even with good acceptance rates, the IP might still be flagged due to spam traps hit or unusual sending patterns detected by Microsoft’s proprietary algorithms.
1 Aug 2023 - Spamresource.com
Expert view
Expert from Email Geeks explains that SNDS color codes reflect SmartScreen content filters' assessment, not a definitive indicator of email delivery status, noting that a red indicator can coexist with good inboxing, and a green indicator can lead to bulk folder delivery.
30 Jul 2022 - Email Geeks
What the documentation says
3 technical articles
Documentation from Microsoft, Gmail, and SparkPost suggests that SNDS (Microsoft's Smart Network Data Services) showing blocked IPs with good acceptance rates and engagement occurs because SNDS offers a limited and potentially skewed perspective on overall deliverability. It only reflects a subset of Microsoft's filtering systems. Other factors, like high engagement (as highlighted by Gmail), signal a positive sender reputation, and discrepancies may arise due to differing filtering algorithms across providers. Therefore, reliance on SNDS alone is insufficient; a comprehensive view demands the use of multiple monitoring tools.
Key findings
- Limited Scope: SNDS data reflects only a portion of Microsoft's filtering systems.
- Incomplete Picture: SNDS data may not directly correlate with inbox placement or overall deliverability.
- Specific Filters: Blocked status in SNDS can indicate issues identified by specific Microsoft filters, irrespective of other performance factors.
- Positive Reputation Signals: High engagement rates usually indicate a positive sender reputation.
- Algorithm Variations: Deliverability discrepancies can occur because of differing filtering algorithms between email providers.
Key considerations
- Use Multiple Tools: Use various monitoring tools to gain a comprehensive understanding of IP reputation and deliverability performance.
- Consider Engagement: Weigh SNDS data against engagement metrics to assess deliverability more accurately.
- Acknowledge Limitations: Be aware of the limited scope of SNDS data when diagnosing deliverability issues.
Technical article
Documentation from Microsoft explains that SNDS data reflects only a subset of Microsoft's filtering systems and may not correlate directly with inbox placement or overall deliverability. Blocked status can indicate issues identified by specific filters, even if other factors suggest good performance.
10 Jun 2023 - Microsoft
Technical article
Documentation from Gmail Postmaster Tools Help explains that high engagement rates signal positive sender reputation. If SNDS shows blocks but engagement is high, the issue might be specific to Microsoft's filters and not a universal deliverability problem.
17 Jan 2022 - Gmail Postmaster Tools Help
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