Microsoft: SNDS Verification Emails not sending

Microsoft's SNDS (Smart Network Data Service) reputation feedback portal is having trouble at the moment. For at least the past week, people have been reporting that attempts to register and verify new IP addresses or ranges with SNDS are failing, because the verification email is not being sent by Microsoft. A few folks have mentioned discussing the issue with Microsoft, and being told to try again -- and have done so, to no avail.

At first I was assuming that Microsoft's SNDS verification request emails were bouncing off of various folks' spam filters. But in my testing, I don't even see any attempt by Microsoft to connect to and deliver a message to my IP range's verification address at my self-hosted email domain. So, something is definitely and significantly broken -- I've got no proof that the SNDS system is even attempting to send verification messages.

Thus, at this time, I don't think it's going to be possible for senders to register sending IP addresses with Microsoft SNDS.

Update: Perhaps I spoke too soon. About 80 minutes after submission, I did receive an SNDS registration verification request email from Microsoft. My test request resulted in an SNDS authorization message with a sender address of and came from the server[]. The message passed SPF (sender SPF authorized) and did have a valid DKIM signature (

Others were still telling me that things were broken as recently as a couple of hours ago; so I'm not sure if things are now fixed, or are variable. I'd suggest also checking your own mail server logs (if possible) to see if Microsoft is actually attempting to connect to your server to try to deliver an SNDS verification request.

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