Outlook complaints live in a tool your seller should open

Answer If a solo ad is going to a lot of Outlook.com addresses, the seller should be looking at Microsoft's own sender data, not only at a blended open rate. Unspam's SNDS guide, updated September 22, 2026, describes that free view: traffic and treatment for the IPs the sender is allowed to see. A buyer rarely has the login. A buyer can still ask whether the seller uses it.

The note that started this: What Is Microsoft Smart Network Data Services (SNDS), How to Check It, Andrian Valeanu, Unspam, updated September 22, 2026.

Outlook is where blended stats go to hide. A list can look alive because one provider is carrying it, while Hotmail has been filing the same from-name for months. The seller averages the two and sells you the average. The repair is not a louder subject line. The repair is a seller who can see the split.

Andrian Valeanu's SNDS guide is the note that started this. The page dates the first publication to February 4, 2026 and the update to September 22, so this is a maintained explanation. SNDS, Smart Network Data Services, is Microsoft's free window for people who send mail and can prove they control the IP space. He describes it as a way to see traffic, delivery, and how Microsoft is treating that sender. In the activity views he explains, RCPT commands are the recipients the conversation got as far as accepting, and DATA commands are the messages the IP actually transmitted. Those are protocol counts. They are not opens, and they are not sales.

What is Microsoft SNDS?

SNDS is Microsoft's free service for senders to see data about mail from their IP addresses to Outlook.com, including traffic and how that mail is being treated.

It is not a public scoreboard. You see the IPs you are authorized to see. A solo ad buyer will not be authorized to see the seller's space, and should not expect to be. The question for the quote is whether the seller, or the platform the seller pays, looks at that window at all. A platform that sends for many customers on shared IPs may be looking at a blend of every customer. That is still more honest than not looking.

Shared IPs cut both ways. Your careful offer can suffer for a neighbor's blast. If the quote brags about a private IP, ask how long that IP has been sending wanted mail. A private IP with no history is a young identity. Safe solo ads sellers can say which of the two you are buying.

What do RCPT and DATA mean in that guide?

Unspam's SNDS guide says RCPT commands reflect how many recipients were accepted and DATA commands reflect how many messages the IP transmitted.

A large DATA count means the IP handed over a lot of messages. It does not mean the messages were wanted, and it does not mean they sat in the inbox. If a seller shows you an SNDS chart and calls it proof of engagement, they are promoting a protocol counter into a relationship. Decline the promotion. The chart is still worth their time, because a reputation view that falls over on the day they mailed a guest offer is a complaint story. You want a seller who can tell that story on their own system.

What should a solo ad buyer ask about Outlook?

Ask what share of the list is Outlook, Hotmail, or Live, and ask whether anyone at the seller looks at SNDS for the IPs that send.

A rough share is enough. Mostly Gmail is an answer. We do not know is also an answer, and it means the open rate they quoted is a stew. If Outlook is a large slice, someone should be watching Microsoft's view of those IPs. If nobody is, the slice is a blind spot you are paying to mail.

Write the share into your notes next to the price. Solo ad pricing for a list that is half a provider the seller never checks is a price for a fog. Pay when the fog has a name, a share, and a person who looks at the tool Microsoft already gives senders for free.