Microsoft Smart Network Data Services (SNDS) is the free tool that shows how Outlook.com, Hotmail, and Live rate your sending IP: message volume, complaint rate, spam-trap hits, and a filter result colored green, yellow, or red. Red means over 90% of your IP's mail to Microsoft is being filtered as
Microsoft Smart Network Data Services (SNDS) is the free tool that shows how Outlook.com, Hotmail, and Live rate your sending IP: message volume, complaint rate, spam-trap hits, and a filter result colored green, yellow, or red. Red means over 90% of your IP's mail to Microsoft is being filtered as spam, which is a crisis. The goal is to stay green.
SNDS is IP-based, so it is most useful if you run a dedicated IP or dedicated cold email infrastructure. Pair it with the Junk Mail Reporting Program (JMRP), Microsoft's feedback loop. This post covers registering both, reading the data, and the 2026 changes that broke some old workflows.
Microsoft SNDS is a free Microsoft service that reports how Outlook.com, Hotmail, and Live evaluate a sending IP address, including daily message volume, spam complaint rate, spam-trap hits, and a green, yellow, or red filter result. It is paired with the Junk Mail Reporting Program, a feedback loop that forwards a copy of each message a Microsoft user marks as junk.
Microsoft's equivalent of Google Postmaster Tools, for its consumer mail. It reports per sending IP: how much mail that IP sent to Microsoft, what share drew complaints, whether it hit any spam traps, and how Microsoft's filters treated it.
Because it is keyed to IP addresses, SNDS tells you the most when you own your sending IP. On a shared IP, it shows the shared pool, not your slice. See dedicated IP vs shared IP email.
Two separate Microsoft programs, and you want both.
SNDS tells you the complaint rate is rising. JMRP tells you which recipients are complaining so you can act.
2026 changes to JMRP: reports are now header-only, and as of June 11, 2026, Microsoft removed the X-HmXmrOriginalRecipient header and stopped appending the message body. You still get the complaint, with less detail attached.
| Color | Meaning |
|---|---|
| Green | Normal sending status |
| Yellow | Caution: some of your mail is being filtered |
| Red | Over 90% of your IP's mail is filtered as spam |
The complaint rate column. Keep it well under 0.3%, ideally under 0.1%, the same thresholds Microsoft and Gmail apply generally. See spam complaint rate benchmark.
Spam-trap hits. Should be zero. Any number here means you are mailing addresses no human opted into, which points at list quality. See how to clean a B2B email list.
Message and RCPT volume. Your daily send count to Microsoft. Useful for spotting a spike that does not match your intended sending.
Sources: Generator Labs and Blue Spirit Hosting.
If you send cold email from Google Workspace or Microsoft 365 mailboxes, you do not control the sending IP. It belongs to Google or Microsoft and is shared with thousands of other tenants. SNDS for that IP shows the pool, not you, so it is not actionable at the individual-sender level.
For shared setups, lean on domain-level signals instead: your Gmail spam rate in Postmaster Tools, seed inbox placement tests across Outlook, and a monthly email domain reputation check. SNDS becomes directly useful the moment you move to a dedicated IP or dedicated cold infrastructure.
If SNDS turns yellow or red, work through this in order.
Red often takes 4 to 12 weeks of clean sending to clear. On a dedicated IP that is badly burned, requesting a fresh IP and warming it can be faster than rehabilitating the old one.
Each tool covers one provider's consumer mail. SNDS covers Outlook.com, Hotmail, and Live. Postmaster Tools covers Gmail. Yahoo Sender Hub covers Yahoo and AOL.
Run all three and you have direct provider data for most consumer inbox placement. What none of them covers is business mail: recipients on Google Workspace and Microsoft 365 tenants, which is most of a B2B cold list. For those, seed placement tests are the only view you get. See email deliverability tools for the full stack.
The Stay-in-Green Rule: by the time SNDS shows yellow, some of your mail is already being filtered, and red means the IP is mostly failing. Green is not a pass to relax; it is the only acceptable state, and a rising complaint rate inside green is where you act.
The rule reframes how to use SNDS. People treat the color as a report card: green is an A, so nothing to do. But the color is a lagging summary. A complaint rate climbing from 0.05% to 0.09% keeps the status green while your reputation degrades, and by the time it flips to yellow, Microsoft is already filtering a meaningful share of your mail.
So watch the complaint rate number and its direction, not just the color. A green status with a flat, low complaint rate is genuinely fine. A green status with a rate that has doubled in a week is a warning the color has not caught up to yet. The quotable version: "The color tells you where you were. The trend tells you where you are going."
Act on the trend inside green, and you will rarely see yellow.
SNDS and JMRP tell you when Microsoft users are complaining. Keeping that from happening comes down to sending mail people actually want, to addresses that are real.
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Microsoft SNDS shows how Outlook.com and Hotmail rate your sending IP, with a green, yellow, or red filter status, a complaint rate column, and spam-trap counts. Register your IP ranges, verify ownership, and set up JMRP alongside it for per-complaint feedback. In 2026, the URL changed, access links expire after 30 days, and JMRP reports are header-only. SNDS is most actionable on a dedicated IP; on shared infrastructure, lean on domain-level signals and seed tests instead. Watch the complaint rate trend inside green, not just the color.
Smart Network Data Services is a free Microsoft tool that reports how Outlook.com, Hotmail, and Live evaluate a sending IP: daily message volume, spam complaint rate, spam-trap hits, and a green, yellow, or red filter result. It is the Microsoft equivalent of Google Postmaster Tools, keyed to IP addresses rather than domains.
Green is normal sending status. Yellow is caution, meaning some of your mail is already being filtered. Red means over 90% of your IP's mail to Microsoft is being filtered as spam, a critical state. Watch the complaint rate trend inside green, because the color lags the underlying reputation.
Go to the current SNDS portal, request access for your sending IP ranges, and verify ownership through the authorization link Microsoft emails to a standard address at the IP's domain or to the network contact. Data appears in 24 to 48 hours. Access links now expire after 30 days, so re-request periodically.
SNDS is data about your sending IPs: volume, complaint rate, trap hits, filter status. JMRP, the Junk Mail Reporting Program, is the feedback loop that forwards you a copy of each message an Outlook.com user marks as junk so you can suppress that address. Set up both.
Not at the individual level. Those services send from shared IPs you do not control, so SNDS shows the shared pool rather than your sending. It becomes directly useful on a dedicated IP. For shared setups, use Postmaster Tools spam rate, seed placement tests, and a monthly domain reputation check.
Microsoft moved SNDS to a new URL, made automated access links expire after 30 days, added a REST API, and tightened JMRP. JMRP complaint reports are now header-only, and as of June 11, 2026, Microsoft removed the original-recipient header and stopped attaching the message body.
LSI keywords: Smart Network Data Services, JMRP, Junk Mail Reporting Program, sending IP reputation, filter result color codes, complaint rate, spam trap hits, Outlook.com deliverability, feedback loop, dedicated IP, Postmaster Tools, 2026 changes
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