Microsoft SNDS & JMRP
Smart Network Data Services (per-IP reputation data for Outlook.com: filter results, complaint rates, trap hits) and the Junk Email Reporting Program feedback loop — data provided, thresholds, and enrollment.
Microsoft's two free programs for senders to Outlook.com (outlook.com, hotmail.com, live.com, msn.com):
- SNDS (Smart Network Data Services) — a dashboard of per-IP sending data: "Deliverability to Outlook.com is based on your reputation. The Outlook.com Smart Network Data Services (SNDS) gives you the data you need to understand and improve your reputation at Outlook.com." It also helps IP owners detect compromised servers, malware, viruses, and botnets on their networks.
- JMRP (Junk Email Reporting Program) — Microsoft's feedback loop: reports on junk email issues reported by Outlook.com users, returning the full message of any email a recipient marked as junk or phishing.
These are the Microsoft counterparts to Google Postmaster Tools and Yahoo's Complaint Feedback Loop. They report on mail to consumer Outlook.com mailboxes, not Microsoft 365/Exchange Online tenants.
Portal migration (2026)
SNDS moved from the legacy sendersupport.olc.protection.outlook.com domain to a new portal at https://substrate.office.com/ip-domain-management-snds/ (short link https://aka.ms/snds). Automated-access consumers had to update URLs off the legacy domain before its June 22, 2026 deprecation. As of July 22, 2026, trap hit counts are no longer shown in SNDS data, to protect the integrity of Microsoft's anti-abuse systems.
SNDS: data provided
Data is aggregated per IP, per day. Around midnight PST a process aggregates the previous day's data (it can take a couple of hours to complete). Data is retained and viewable for 90 days.
| Field | Meaning |
|---|---|
| Activity period | First and last hour of the PST day during which activity was seen from the IP |
| RCPT commands | Count of RCPT TO commands issued. Benchmark: more than a third of IPs sending to Outlook.com keep the fraction of RCPT commands that don't result in message recipients under 10% — a high failure fraction indicates list-quality problems or namespace mining |
| DATA commands | Count of actual message transmissions |
| Message recipients | Final count of intended recipients. Well-behaved senders show only minor discrepancy vs. RCPT count |
| Filter result | Color-coded spam-filter verdict for the IP's mail that day (see below) |
| Complaint rate | Complaints ÷ message recipients. Benchmark: more than 30% of IPs sending to Outlook.com keep complaint rate below 0.3% |
| Trap hits | Messages sent to nonexistent trap accounts maintained by Outlook.com. Legitimate senders hit them rarely; spammers cannot easily avoid them. Removed from reports as of July 22, 2026 |
| Sample HELO / MAIL FROM | Actual examples of the SMTP identity commands seen from the IP — useful for spotting traffic that isn't yours (compromise, spoofed infrastructure) |
Filter-result thresholds
| Color | Meaning |
|---|---|
| Green | Spam < 10% of the IP's mail |
| Yellow | 10% ≤ spam ≤ 90% |
| Red | Spam > 90% |
How to read SNDS in a deliverability workflow
- Red/yellow filter results with normal volume → content or reputation problem; check authentication and complaint drivers.
- Complaint rate ≥ 0.3% → above the practical safe line (the same figure Yahoo and Gmail publish as a hard threshold); tighten list hygiene and consent.
- Unexpected volume, HELO values, or trap hits → likely compromised host or unauthorized use of your IP space.
- No data for an IP usually means it sent too little mail to Outlook.com that day to be reported.
SNDS: enrollment and access
- Sign in to SNDS with a Microsoft Account.
- Request access to the IPs (or CIDR range / ASN) you are responsible for.
- SNDS determines authorized contacts via reverse DNS and WHOIS lookups on the range and offers the associated email addresses; ranges up to a /23 can be authorized via reverse DNS when the range has consistent domain patterns.
- Click the link in the verification email sent to the chosen address to confirm authorization.
Automated access: SNDS provides a simple data-access URL (keyed, no interactive login) intended for automated systems to pull the daily data — suitable for feeding monitoring/alerting.
JMRP: the Outlook.com feedback loop
- Free service providing "reports on junk email issues reported by Outlook.com users."
- Returns the full message with headers of any email a recipient marked as junk or phishing.
- Purpose: identify recipients who no longer want your mail (remove them immediately) and spot content/segments driving complaints.
- Enrollment: through the SNDS portal at
https://substrate.office.com/ip-domain-management-snds/snds/jmrp(requires the same Microsoft Account sign-in and IP authorization as SNDS). - Feedback typically starts arriving within as little as 72 hours of enrollment.
- Enrolling in JMRP is Microsoft's documented remediation step for the
550 SC-004block (IP blocked due to complaints) — see Microsoft Sender Requirements.
Unlike ARF-based feedback loops at some providers, JMRP reports are keyed to sending IP, so the mail must come from IP space you have authorized in SNDS. Process every JMRP report as an unsubscribe: continuing to mail a complainer directly raises the SNDS complaint rate and the odds of an SC-004 block.
Related
- Microsoft Sender Requirements — policies, the 2025 authentication mandate, and SMTP error codes
- Foundations of Email Deliverability — complaint and trap signals in reputation systems
- IP Warm-Up Recommendations — use SNDS to watch new IPs during warm-up