What’s SNDS and how does it complement inbox monitoring?

If you've been watching your Gmail Postmaster Tools dashboard and everything looks fine, but your Outlook recipients still seem to be having trouble, there's a good reason for that. Gmail and Microsoft run completely separate reputation systems. What looks healthy on one tells you nothing about the other.

That's where Microsoft SNDS (Smart Network Data Services) comes in. It's Microsoft's free feedback program that shows you how your sending IPs are performing specifically with Outlook.com and Hotmail inboxes.

Here's what SNDS shows you once you're set up:

• IP reputation status: A color-coded rating for each of your sending IPs. Green means you're in good shape. Yellow is a warning. Red means Microsoft is likely filtering or blocking your mail.
• Complaint rate data: The percentage of your emails that Microsoft recipients marked as spam. This is Microsoft-specific data you won't find anywhere else.
• Spam trap hits: Whether your sends are hitting Microsoft's own trap addresses. If this is lighting up, your list has a problem that needs attention now.
• Mail volume: A rough daily count of messages sent from your IPs to Microsoft recipients.

To get access, you'll need to go to postmaster.live.com/snds and request access for each IP address you send from. Microsoft sends a verification email to the postmaster address for each IP, so you'll need access to those accounts. It takes a day or two to get approved, and then data starts populating from there.

One thing worth knowing: SNDS is IP-based, not domain-based. That's the opposite of how Gmail Postmaster works, which is domain-based. So if you're on shared IPs through your ESP, the data you see in SNDS will reflect the behavior of all senders on those IPs, not just you. If you're on dedicated IPs, every data point is yours.

Together, Gmail Postmaster and SNDS give you a real picture of how the two largest consumer mailbox providers see your sending reputation. Using only one of them is like checking the weather in one city when your mail is being delivered across two. You need both.

If your SNDS shows red IPs or high trap hits, that's not something to sit on. Our SOS hotline is free and we can help you figure out what's actually going on before it gets worse.