Hi,
Add this to smtp header
Precedence: bulk
List-Unsubscribe: <mailto:<%= provider.errorAddress !='' ? provider.errorAddress:delivery.mailParameters.errorAddress %>?subject=unsubscribe<%=escape(message.mimeMessageId) %>>
For bulk upload, you can try to do it in a JS. Moving forward you can add a typology rules to add it automatically to all deliveries.
Thanks,
David