How do you sync suppression lists across apps?

Suppression synchronization prevents sending to opted-out contacts across systems:

Critical suppressions to sync: Unsubscribes from any channel. Hard bounces and invalid addresses. Spam complaints. Legal suppression requests (GDPR deletion, etc.).

Sync mechanisms: API integration: Real-time suppression updates between systems. Webhook notifications: Instant alerts when suppression occurs. Scheduled exports: Regular file-based sync for systems without API. Centralized management: Single source of truth that all systems reference.

Timing considerations: Suppression sync should be real-time or near-real-time. Delays risk sending to newly suppressed addresses. Prioritize suppression sync over other data.

Verification: Regularly audit suppression consistency across systems. Test that suppressions propagate correctly. Monitor for sync failures.

A suppression missed in one system defeats suppression everywhere. Consistency is essential.