tpokorra Sorry I'didnt read your reply.
To answer to your question:
It would have to be the DIskussion. So if a discussion has no replies after 48h, a notification is triggered.
We have now solved it so that we push the notification mails into a web tool, which makes a ticket out of the notification. The ticket has a SLA of 48 hours, after that we check if an answer exists on the discussion. If no, we reply as a company. If yes, we close the ticket.
Example of such a tool is raisaticket.