Deliverability
What is Microsoft SNDS (Smart Network Data Services)?
Microsoft's free portal that reports IP reputation, traffic, and spam data for senders mailing into Outlook, Hotmail, and Live.
Smart Network Data Services is Microsoft's postmaster program that, once a sender verifies control of an IP range, exposes per-IP data including message volume, spam-trap hits, complaint rates, and a red/yellow/green filter result. It is the Microsoft counterpart to Google Postmaster Tools and is usually paired with Microsoft's separate Junk Mail Reporting Program (JMRP) feedback loop. The data is reported per IP, which makes it most actionable on dedicated IPs.
Why it matters for cold email
Microsoft mailboxes are notoriously opaque and do not expose a rich aggregate view, so SNDS is the primary window into why cold mail is being deferred or junked at Outlook. Monitoring SNDS lets senders catch trap hits and complaint spikes early and prove IP health during warmup before reputation damage spreads.
Related terms
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