Smart Network Data Services (SNDS)

Smart Network Data Services (SNDS) is a free tool provided by Microsoft that offers visibility into how Microsoft’s Outlook infrastructure views your sending IPs. SNDS gives senders access to key deliverability indicators, including: 

• Email volume 
• Spam trap hits 
• Complaint rates 
• IP reputation status 

These insights help senders understand how Microsoft evaluates their traffic and whether their emails are likely to reach the inbox – or be filtered as spam. 

Monitoring SNDS is especially important for high-volume senders using dedicated IPs. It’s not real-time and doesn’t cover domain reputation, but when paired with other tools (like Google Postmaster Tools), it can help diagnose deliverability issues and protect your sender reputation.