What is outbound filtering and why is it used?

Outbound filtering scans messages before sending to prevent spam, malware, or policy violations from leaving your infrastructure. It protects your sending reputation by catching problems before they reach recipients and trigger complaints.

Filtering catches: accidental spam from compromised accounts, malware attachments, policy violations in user-generated content, and misconfigured systems sending unintended bulk messages. Better to block internally than damage reputation externally.

ESPs implement outbound filtering automatically. Organizations with custom infrastructure need dedicated filtering solutions. Configuration balances sensitivity against false positives that block legitimate email. Monitoring filter actions reveals potential security issues or policy problems.