HubSpot directly, Salesforce through the HubSpot sync you already run, or a spreadsheet in your own column format.
HubSpot, Salesforce or a Spreadsheet
HubSpot: released contacts are written directly, deduplicated by work email
Salesforce: contacts reach Salesforce through the HubSpot to Salesforce sync you already run
Spreadsheet: released contacts can be downloaded in your own column format for any other system
Only Released Contacts
Nothing reaches the CRM until an employee releases it. Every record carries who released it and when, and every export can be re-downloaded for 24 months.