Microsoft SNDS

Microsoft SNDS is a free web service that helps senders and internet service providers understand email sending reputation with Outlook.com. It provides detailed data about individual IP addresses and insight into how Outlook.com views the health of an IP space. Its Junk Email Reporting Program can send reports when users mark messages as junk, and the portal lets users view IP data and manage feedback loop settings together. SNDS can help IP owners detect compromised servers, malware, viruses, and botnets. The Smart Network Data Services (SNDS) plan is free. It provides sender reputation and blocklist monitoring, as well as API access; inbox placement and spam trap monitoring are not provided. To gain access, users sign in with a Microsoft Account and request authorization for IPs they manage. Network access expires 10 months after approval or migration, requiring periodic ownership reattestation. Data Reports stopped including trap hit counts starting July 22, 2026. For urgent Outlook.com delivery issues, Microsoft advises contacting sender support with someone familiar with the issue and email infrastructure.

SNDS offers Outlook.com focused IP reputation data and feedback loop tools at no cost. Users need to request authorization for their IPs and reattest ownership when access expires.

SNDS suits senders and ISPs responsible for email deliverability and sending reputation with Outlook.com. It is relevant to IP owners who need IP data, feedback loop settings, or tools to spot compromised systems.