What are “spam fingerprints”?

Spam fingerprints are unique identifiers computed from message characteristics. Filters create fingerprints by hashing content elements, allowing comparison across messages to identify related spam campaigns.

Fingerprint elements may include: text content (normalized), image hashes, link patterns, and structural characteristics. Similar fingerprints indicate related messages even with superficial variations.

Uses: identifying campaign-related messages when one is confirmed spam, tracking spam volume from specific operations, and enabling blocklist sharing based on fingerprint rather than exact content.