Northern Trail Outfitters has acquired a new company and is importing customer data to Marketing...

Because NTO is importing an entirely new dataset of customer records from a newly acquired company, and needs an ongoing, automatically-enforced safeguard ensuring that any email address matching a previously recorded opt-out is excluded from commercial sends — not just a one-time manual check — an Auto-suppression list, dynamically populated and refreshed against the known opted-out addresses, is the correct feature: once configured, it automatically applies to future qualifying sends without requiring the marketer to manually re-attach a static list to each individual send, providing durable, ongoing compliance protection as the newly imported and existing populations are merged. A standard Suppression list (C) is a static, manually-attached list that must be explicitly selected on each individual send — it does not automatically and continuously enforce itself across all future sends the way an auto-suppression list does, making it a less robust, more maintenance-dependent safeguard for this ongoing compliance concern. ' Exclusion Script ' (A) and ' Exclusion List ' (B) are not standard, documented Marketing Cloud feature names for this purpose. Reference: Auto-Suppression Lists, Opt-Out Compliance in Data Migrations.