What are the volume requirements for SNDS and GPT data?
Michael Ko
Co-founder & CEO, Suped
Published 8 Jul 2025
Updated 14 Aug 2025
9 min read
Summary
Understanding the minimum sending volumes required to access data in Microsoft's Smart Network Data Services (SNDS) and Google Postmaster Tools (GPT) is crucial for email senders. These platforms provide invaluable insights into your email deliverability and sender reputation, but only if you meet their specific data reporting thresholds. Typically, a certain daily email volume is necessary for these tools to begin displaying meaningful metrics related to your IP and domain performance.
Key findings
SNDS volume: Microsoft SNDS requires sending at least 100 messages per day from a specific IP address for traffic and spam data to be visible. Below this threshold, data for that IP may not be present.
GPT volume: While official documentation varies, general consensus among deliverability professionals indicates that Google Postmaster Tools also requires a daily sending volume, often cited as around 100 messages per day, for data to populate for an IP or domain. Some historical information suggested 1000 messages, but 100 is now more widely accepted.
Data accuracy: Even if you meet the minimum volume, the granularity and reliability of the data increase with higher sending volumes. Low volumes might provide incomplete or delayed insights.
Reputation impact: Both platforms can cease providing data if your sender reputation deteriorates significantly, indicating that high bounce rates or spam complaints might lead to data suppression.
Key considerations
Consistent sending: Ensure consistent daily sending above the minimum thresholds to maintain continuous data flow and accurate reporting in both Gmail Postmaster Tools and SNDS.
IP warm-up: When warming up a new IP, gradually increase your sending volume to hit these thresholds. This allows you to monitor initial performance and adjust as needed, as discussed in recommended initial email sending volumes.
Monitoring tools: Regularly check SNDS and GPT dashboards to ensure data is populating. If not, evaluate your sending volume and reputation metrics. The SNDS FAQ provides further details on data display.
Domain reputation: Be mindful that severely poor domain or IP reputation can lead to data suppression, regardless of volume. Focus on maintaining a healthy sending reputation to ensure continued access to these vital insights.
What email marketers say
Email marketers often discuss the practical implications of volume requirements for SNDS and GPT. Their experiences highlight the nuances of these thresholds, emphasizing that while official numbers exist, real-world data visibility can be influenced by factors beyond just raw volume, such as list quality and recipient engagement. Marketers frequently share anecdotes and observations about how quickly data appears and what might cause it to disappear or be unreliable.
Key opinions
SNDS threshold confirmation: Many marketers confirm the 100 message per day minimum for SNDS data to populate, noting its consistency for most IPs.
GPT volume variations: There's been some confusion regarding GPT's exact threshold, with some marketers citing 1000 messages daily in the past, but current experiences lean towards a 100 message per day requirement similar to SNDS.
Data suppression: Marketers are aware that consistently poor sending practices, like high spam rates or bounce rates, can lead to their data being suppressed or entirely removed from these Postmaster tools, regardless of volume. This ties into managing your Google Postmaster Tools Domain Reputation.
Initial visibility: New senders often observe a slight delay before data first appears, even after hitting the initial volume requirements.
Key considerations
Daily volume consistency: It's not just about hitting the threshold once, but consistently sending above it daily to ensure data continues to flow into SNDS and GPT.
Avoiding data loss: If you're experiencing email deliverability issues, ensure your sending volume isn't dropping below these minimums, as losing access to data can complicate troubleshooting. This is especially true for Microsoft Outlook.com deliverability.
Early warning signs: Use these tools as early warning systems. If data stops appearing, it could signal a significant reputation problem that needs immediate attention, similar to how GPT helps unlock delivery analytics for many.
IP vs. domain data: Remember that data is often reported per IP address in SNDS, while GPT provides both IP and domain level insights, both subject to volume requirements.
Marketer view
Email marketer from Email Geeks notes that based on Microsoft's documentation, if you send less than 100 messages from a particular IP on a given day, you might not see any mail traffic or spam data for that IP in SNDS. This minimum threshold is crucial for reliable reporting.
27 Sep 2019 - Email Geeks
Marketer view
Email marketer from Email Geeks suggests that Google Postmaster Tools (GPT) likely has a similar daily volume requirement to SNDS, estimating it to be around 100 messages per day. This consistency across major providers helps senders manage expectations.
27 Sep 2019 - Email Geeks
What the experts say
Deliverability experts provide a deeper understanding of the volume requirements, explaining the underlying mechanisms and potential pitfalls. They emphasize that while specific numbers are cited, the overarching goal of these Postmaster tools is to provide insights to legitimate senders while denying data to abusive ones. Experts often focus on the broader context of sender reputation, highlighting how consistent, healthy sending volumes contribute to reliable data reporting.
Key opinions
Threshold as a minimum: Experts clarify that the 100 message daily threshold for both SNDS and GPT is a minimum for data to appear, not necessarily for comprehensive insights. Higher volumes generally lead to more granular and reliable data.
Reputation-based data suppression: It is widely accepted that mailbox providers (MBPs) will suppress or restrict data access for domains or IPs with consistently poor reputations (e.g., high spam complaints, hitting spam traps), regardless of the raw sending volume. This is a crucial aspect of their anti-abuse measures.
Data latency: Data in these tools is not real-time. Experts advise that insights typically reflect activity from the previous 24-48 hours, requiring senders to look at trends rather than immediate changes.
Domain vs. IP data: While SNDS focuses heavily on IP reputation, GPT provides a valuable combination of IP and domain reputation data. Both require sufficient volume to be reported accurately.
Key considerations
Reputation first: Focus on building and maintaining a strong sender reputation through good list hygiene, relevant content, and engaged subscribers. Without it, even high volumes won't guarantee data access in SNDS or GPT.
Dedicated IP monitoring: For senders on dedicated IPs, ensure each IP consistently hits the volume threshold to get individual performance reports. This is critical for managing SNDS blocking issues.
Volume for stability: While 100 messages is a minimum, consistent daily sending well above this (e.g., thousands) provides a more stable and accurate data set, allowing for better trend analysis and proactive issue identification, as often discussed on Word to the Wise.
Proactive monitoring: Utilize these tools daily. If you notice a sudden drop in reported volume, even if your actual sending volume hasn't changed, it could be a sign that you've hit a blocklist or your reputation has declined.
Expert view
Deliverability expert from SpamResource emphasizes that mailbox providers use volume thresholds not just to limit data, but to filter out insignificant senders or those attempting to game the system. Consistent, legitimate volume is key to being taken seriously.
20 Feb 2024 - SpamResource
Expert view
Deliverability expert from Word to the Wise confirms that while 100 emails per day is often cited for Postmaster Tools, achieving full data granularity typically requires significantly higher, consistent daily sending volumes. Small volumes can lead to sparse data.
10 Mar 2024 - Word to the Wise
What the documentation says
Official documentation from Microsoft and Google provides the authoritative guidelines for accessing data within their respective Postmaster tools. While direct and explicit volume numbers can sometimes be elusive or subject to change, the core principles revolve around ensuring enough legitimate traffic to generate meaningful metrics. These documents often highlight that data visibility is tied to both sending volume and sender reputation, aiming to provide insights to good senders while protecting their systems from abuse.
Key findings
SNDS minimum: Microsoft's Smart Network Data Services explicitly states that mail traffic and spam data may not be present for IPs that sent fewer than 100 messages on a given day. This is a clear threshold for data availability.
GPT data conditions: Google Postmaster Tools documentation indicates that data is only displayed if there is a significant daily volume of email traffic from your IPs to Gmail users, and if your volume is large enough for reputation data to be calculated. It does not provide an explicit number but implies a substantial threshold.
Reputation dependency: Both platforms imply that data is contingent on maintaining a good sender reputation. If mail is consistently being filtered to spam or rejected due to poor sending practices, data may be incomplete or suppressed.
Data aggregation: Documentation suggests that data is aggregated over time (e.g., daily) and may not be real-time, requiring a consistent flow of emails to provide accurate trends.
Key considerations
Adherence to guidelines: Always refer to the latest official documentation for SNDS and GPT, as volume requirements and data display policies can evolve with changes in internet service provider (ISP) filtering and anti-abuse strategies. This also applies to Google's bulk sender guidelines.
Troubleshooting data gaps: If you're not seeing data, first verify that your IP or domain meets the stated or implied volume requirements. If volume is sufficient, then investigate potential reputation issues.
Understanding limitations: Be aware that even with data, these tools offer a high-level overview. For deeper insights, you'll still need to rely on your own sending logs and bounce data, as highlighted in expectations for ESPs sharing bounce data.
Technical article
Official Microsoft Documentation for SNDS clearly states that mail traffic and spam data will not be available for IPs sending less than 100 messages daily. This minimum volume is foundational for any data reporting.
10 Mar 2023 - Microsoft SNDS FAQ
Technical article
Google Postmaster Tools Help documentation indicates that all data in GPT is only available when there is a substantial daily volume of email traffic from your IP addresses to Gmail users. It implies that lower volumes might not yield any data.
