Microsoft SNDS: Setup and Reading the Data

Microsoft SNDS (Smart Network Data Services) is Outlook.com's free reputation dashboard for sending IP addresses. It shows how many messages an IP sent to Outlook.com, Hotmail and Live addresses each day, the share that Microsoft's filter judged as spam (green, yellow or red), the complaint rate and whether the IP is blocked. You get access only to IPs you can prove you control, so it is a tool for whoever runs the sending server.

We make Outreach2day, cold email infrastructure: domains, mailboxes, warmup and a sequencer in one product. The facts below come from Microsoft's SNDS site and FAQ, checked on October 15, 2026.

What Changed in 2026

The SNDS portal moved. Its announcement, last updated September 22, 2026, reads: "Welcome to the new SNDS portal. This site is replacing the previous site at https://sendersupport.olc.protection.outlook.com/snds/". The new address is substrate.office.com/ip-domain-management-snds, and the old one redirects there.

Access now expires. Microsoft's FAQ: "Once access is approved, it remains valid for 10 months from the approval date. SNDS sends three reminders before access expires, approximately three, six, and nine months after approval." An approved reattestation renews it for another 10 months; without one, "access to the network's SNDS data will be removed." Microsoft also says the deadline date in the first reminder email was wrong and is being corrected.

Who Can Use SNDS

SNDS works per IP address. To see an IP's data you prove you control it:

1. Sign in with a Microsoft account and open Request Access.

2. Enter an IP, an IP range or an ASN you own.

3. SNDS finds the addresses it trusts for that range, through reverse DNS (postmaster@ and abuse@ at the hosts' domain, for ranges up to a /23) and through RDAP records of the IP allocation.

4. Pick one you can receive mail at and click the link in the authorization email.

Microsoft is clear that it "cannot manually adjust authorizations." If the authorization addresses are not yours, someone who receives mail there has to approve you.

What this means for cold email

Most cold email senders don't control their sending IPs:

On a shared IP, SNDS reports every sender on that IP together. Microsoft's FAQ says the same about complaints: "If you are behind a shared IP, you will see all the spam complaints regardless of the sending domain."

Also note the scope: Microsoft describes SNDS as data about "reputation at Outlook.com", its consumer service (outlook.com, hotmail.com, live.com). Its documentation says nothing about business recipients on Microsoft 365, which Exchange Online Protection filters.

How to Read the SNDS Data

The View Data page lists one row per IP per day. Microsoft aggregates each day after about midnight Pacific time, which "can take a couple hours," and keeps the data for 90 days. IPs that sent fewer than 100 messages that day may show no traffic or spam data.

Green, yellow and red

The filter result is the share of messages Microsoft's spam filter gave a spam verdict:

Microsoft notes the yellow band is wide on purpose, to give spammers less to tune against. Its tip: compare with your other IPs. If the rest are green, a yellow IP is probably near 10%; if most are red, near 90%. One message to ten recipients counts as ten verdicts.

Complaint rate and RCPT benchmarks

Microsoft gives two reference points: "more than 30% of the IPs sending mail to Outlook.com keep their complaint rate at less than 0.3%," and "more than a third of IPs" keep the share of RCPT commands that don't become recipients "under 10%." A high gap between RCPT and recipients means old lists or address guessing; clean the list with the email list cleaner before the next send.

IP Status

View IP Status lists IPs with an abnormal state in the last 24 hours, with no history: Blocked (mail is refused), Bot (bot-like behavior seen) and Junked (messages are being junked, and further bad mail can lead to a block). For a block, Microsoft points you to its sender support pages; the delist portal at sender.office.com handles bounces such as 5.7.606 to 5.7.649, "Access denied, banned sending IP." The email bounce decoder reads those bounces.

Junk Mail Reporting Program

JMRP sends you a copy of each message an Outlook.com user marks as junk, for the IPs you have registered. The copies show which campaign drew the complaints. Enroll from the SNDS menu.

SNDS and Google Postmaster Tools

Neither documents data for business mailboxes, which are most of a B2B cold email list. Google Postmaster Tools covers the Gmail side.

When SNDS Is Not Available to You

If you send from mailboxes on someone else's servers, use the signals you do have:

• Bounce texts. Microsoft names the cause in the code: 5.7.515 for authentication, 5.7.1 with a block list, 5.7.606 to 5.7.649 for a banned IP. See Outlook blocking cold email.

• Header verdicts. A test copy in an Outlook.com mailbox carries SCL, BCL and SFV values; the email header analyzer decodes them.

• Your provider. Ask which IPs your mailboxes send from and whether they watch them in SNDS.

FAQ

Is Microsoft SNDS free?

Yes. You need a Microsoft account and control of the IP addresses you register.

Can I use SNDS for a domain?

No. SNDS reports per IP address. For domain-level data at Gmail, use Google Postmaster Tools.

Why does SNDS show no data for my IP?

The IP sent fewer than 100 messages to Outlook.com that day, the day has not been processed yet, or your access expired. Data for a day appears a few hours after midnight Pacific time.

What does a yellow SNDS result mean?

Between 10% and 90% of the IP's messages that day got a spam verdict. Compare with your other IPs to place it within that range.

Does SNDS cover Microsoft 365 recipients?

Microsoft describes SNDS as Outlook.com data: outlook.com, hotmail.com and live.com addresses. It documents nothing for Microsoft 365 business mailboxes.

Why did my SNDS access disappear?

Access lasts 10 months from approval. Submit a reattestation request before the expiry date shown on the Access Control page.

Sources

Checked October 15, 2026:

• Microsoft SNDS portal: new portal announcement (September 22, 2026), replacement of the old site, reattestation reminder correction.

• Microsoft SNDS FAQ: authorization through reverse DNS and RDAP, no manual changes, 10-month access and reminders, data columns, color thresholds, 100-message floor, complaint and RCPT benchmarks, shared IPs, IP status states, 90-day retention, CSV export and automated access.

• Microsoft Learn: Non-delivery reports in Exchange Online: 5.7.606 to 5.7.649 banned sending IP and the delist portal.

Outreach2day runs the sending servers behind its mailboxes, with SPF, DKIM and DMARC on your own domains and warmup included, at $2.50 per mailbox a month.