Standard blacklist monitoring tells you whether your sending IPs appear on public RBLs. It doesn’t tell you how Microsoft specifically views your mail. That’s a separate reputation system, and it matters a lot: Outlook.com, Hotmail, and MSN together represent a significant share of consumer email. Generator Labs now integrates directly with Microsoft Smart Network Data Services (SNDS) inside your blacklist monitoring dashboard.
What SNDS Provides
SNDS is a free Microsoft program that gives senders data about mail flowing from their IP addresses into Microsoft’s mail infrastructure. The metrics it returns include:
- Message volume from each IP
- Spam complaint rate
- Spam trap hits
- Overall IP status (Green / Yellow / Red)
- Filter result breakdown
A Red status from SNDS means Microsoft is actively blocking or heavily filtering mail from that IP. Yellow is a warning that reputation is declining. Most teams only discover this when customers start reporting missing mail.
Why It’s Worth Monitoring Separately
SNDS status doesn’t always correlate with your RBL status. You can be clean on every public blocklist and still have a Yellow or Red SNDS rating because of complaint rates, trap hits, or sending patterns that Microsoft’s filters flag specifically. The inverse is also true: an SNDS Green rating doesn’t mean you’re clean on all public RBLs.
Treating SNDS as a separate signal, alongside your regular blacklist monitoring, gives you a more complete picture of your sending reputation and catches Microsoft-specific issues before they escalate.
Setup
Go to RBL Monitoring > SNDS in the portal and add your SNDS access key. Microsoft issues one key per registered IP range. Once connected, Generator Labs pulls your SNDS data automatically and surfaces status changes alongside your other monitoring results.
Setup instructions are in the SNDS documentation.
