How to handle unsubscribed cold contacts in marketing lists?

Unsubscribes from cold outreach must be honored across all communication types.

Core principle:

An unsubscribe means stop contacting me, not just stop this sequence

Honor across all channels and systems

Don't try to parse different types of opt-out

Suppression handling:

Add cold unsubscribes to master suppression list

Sync suppression across cold tools and marketing ESPs

Check suppression before any send, regardless of source

Never circumvent with domain changes or new data

Data source management:

Screen all new data against suppression before import

Same email from different source doesn't override opt-out

Purchased lists must be checked against internal suppression

System configuration:

Automate suppression sync between platforms

Test that suppression works across all sending channels

Verify CRM integration respects suppression

Audit periodically for sync failures

Edge cases:

If someone unsubscribed then explicitly re-subscribes, document carefully

Re-subscription should be proactive, not assumed

Maintain history of opt-out and any re-consent