Microsoft SNDS and JMRP: the only Outlook sender data you get

Microsoft's sender tools are the Outlook-side equivalent of Google's Postmaster Tools, split into two services. SNDS (Smart Network Data Services) reports what Microsoft observed about traffic from your IPs. JMRP (Junk Mail Reporting Program) forwards you a copy of each message an Outlook user marked as junk. Neither is a blocklist lookup, because Microsoft does not publish one.

SNDS is per IP, not per domain

This is the structural difference from Google. Postmaster Tools reports on your domain; SNDS reports on IP addresses, and you only get data for IPs you can prove you control. Registration asks you to nominate a range and then validates it, usually by emailing an address at the WHOIS contact or a conventional role address for the netblock.

The practical consequence: if you send through a shared pool, SNDS is not available to you. The IPs belong to your ESP. You can still register for JMRP in some configurations, and your provider may expose its own aggregate view, but the per-IP table is theirs, not yours.

What the data shows

Once an IP has traffic, SNDS gives you a daily row per IP:

Treat the colours as a summary rather than a measurement: green means nothing is currently wrong, yellow means your complaint rate or trap hits are elevated enough to affect filtering, and red means filtering is actively working against you. A green grade is not evidence of good placement — it is evidence of no recorded problem, which is weaker.

The two columns that drive the grade are complaint rate and trap hits. Trap hits in particular are an acquisition verdict: Microsoft's traps are addresses no human ever gave you, so a non-zero count means scraped, purchased or unverified addresses are in your list. No warm-up fixes that.

JMRP is the actionable half

SNDS tells you a rate. JMRP tells you *who*. Enrol your IPs and nominate an address to receive the reports, and every junk click produces a copy of the message with the recipient intact.

What to do with it:

1. Suppress the recipient permanently, in the system that actually sends, not in a spreadsheet.
2. Automate the parsing. A human reading a JMRP mailbox will fall behind during the exact week it matters.
3. Look for pattern. If reports cluster on one campaign, one segment or one template, you have found your complaint source.

A complaint is worth more signal than a bounce on Microsoft's stack. Acting on JMRP within hours is one of the few things that visibly moves a yellow grade back toward green.

Setting both up

1. Go to Microsoft's sender support site and register for SNDS with the IP range you send from.
2. Complete the ownership validation for that range — this is the step that stalls, so start it early.
3. Register for JMRP for the same IPs, pointing it at a monitored mailbox you can parse.
4. Wait. Neither tool backfills; data begins when registration completes and only on days you actually sent.
5. Bookmark the Office 365 anti-spam delist portal separately. It is a one-off mitigation request for a blocked IP, not a monitoring tool.

SNDS compared with Google Postmaster Tools

The retirement matters for how you read advice: Google redirected senders to v2 from 30 September 2025 and v1 was gone by the end of 2025, and the domain and IP reputation dashboards are permanently gone. v2 reports spam rate, authentication, delivery errors and compliance status, with a Deliverability analysis report added in June 2026. So on the Google side you watch a rate against the 0.30% threshold; on the Microsoft side you watch a colour and a complaint feed. They are not comparable numbers and neither substitutes for a placement test.

What not to do

• Do not treat green as proof of inbox placement. It means no recorded problem on those IPs, not that your mail reached Primary inboxes.
• Do not register and then ignore it. SNDS data has no history before you enrol, so the archive you want during an incident is the one you started months earlier.
• Do not use the delist portal as a routine. Repeated requests without a behaviour change are declined, and the block returns.
• Do not go looking for a Microsoft blocklist to query. There is none. If a tool claims to check whether you are on Microsoft's list, it is inferring from bounce text at best.
• Do not ignore trap hits because the number is small. A handful of traps on a modest send is a high rate, and it indicts your list source.
• Do not assume SNDS covers Microsoft 365 tenants. It reports on consumer-side filtering; a hosted tenant's own policies and limits are a separate matter.

How MailPilot helps

MailPilot warms Outlook and Microsoft 365 mailboxes over OAuth, or any SMTP/IMAP sender, with a ramp designed not to produce the volume spikes that turn an SNDS grade yellow. Its seed-inbox network measures Microsoft placement directly, which is the thing SNDS cannot tell you, and it tracks each mailbox's reputation daily alongside SPF, DKIM and DMARC checks.