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.