Contact importing involves uploading a CSV, connecting via API, or syncing from another platform. Best practices: only import opted-in contacts, map custom fields correctly, tag the import source, run verification before import, and set up a re-permission campaign if the list is old. Importing purchased or scraped lists violates most ESPs' terms of service and can destroy sender reputation. MisarMail supports CSV import, API import, Zapier sync, and direct CRM integration with automatic verification.