Microsoft SNDS review
A free Microsoft-focused diagnostic service for IP reputation and Outlook.com filtering signals.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Microsoft SNDS is a free web service for email senders, internet service providers, and network administrators who control email-sending IP ranges. It focuses on Microsoft-specific diagnostics, showing IP-level email traffic and message-recipient reporting, sender complaint rates, aggregate Outlook.com spam-filter results, and status indicators for blocked, bot, or junked IPs. Access is web-based and requires Microsoft account authentication, along with authorization for the relevant IP range or ASN.
Its strongest fit is for teams that need a focused view of how Outlook.com evaluates sending infrastructure. The service also incorporates Junk Email Reporting Program feedback and displays virus, malware-hosting, and open-proxy detection indicators. CSV export supports reporting workflows, while automated data access can connect the service's information to internal systems. These capabilities make SNDS useful for diagnosing Microsoft-specific reputation concerns without a paid plan.
SNDS is narrower than a full email deliverability monitoring suite. It provides sender reputation and blocklist monitoring, but not inbox placement monitoring or spam-trap monitoring. The published service details also center the experience on Outlook.com data rather than broad mailbox-provider coverage. Choose Microsoft SNDS when free IP-level traffic, complaint, filtering, and security indicators are the priority. An alternative is more suitable when the requirement is cross-provider inbox placement analysis or broader authentication and deliverability monitoring.
Microsoft SNDS pros and cons
- Where it wins
- Free reporting for traffic, complaints, filtering, and IP status
- CSV export plus automated data access for systems
- Includes malware, virus, and open-proxy indicators
- Where it doesn't
- Focused on Outlook.com-specific deliverability signals
- Does not provide inbox placement monitoring
- Requires authorization for the relevant IP range or ASN
Microsoft SNDS fact sheet, pricing and score →
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