What’s the difference between content-based and behavioral filtering?

Two filtering approaches:

Content-based filtering:

Examines message text, subject lines, HTML structure

Scans links and attachments

Looks for spam patterns and keywords

Can be triggered by single message

More predictable, testable

Behavioral filtering:

Examines sender reputation

Considers recipient engagement history

Analyzes sending patterns and volume

Builds over time

Harder to test directly

Modern filtering: Uses both together. Good reputation can overcome suspicious content. Bad reputation makes everything suspicious.

Focus on behavior/reputation for long-term deliverability, content for immediate issues.

The cargo is inspected, but so is the ship's history and the captain's reputation.