What are reputation APIs?

Reputation APIs provide programmatic access to sender reputation data. Query an IP or domain; receive reputation assessment. Enables real-time filtering decisions based on current threat intelligence.

Major APIs: Spamhaus (blocklist queries), Cisco Talos (reputation scores), Validity (Sender Score), and MBP-specific tools. Different APIs provide different perspectives and data types.

Integration: email security systems query APIs during message processing, using responses to inform filtering. API response time affects mail flow; reliability is critical for production use.