Hi @MatteMa,
Once the email addresses return a hard bounce Adobe campaign marks the recipient profile in the Quarantine list. More details on this topic are here.
You can go to the following path Administration>Campaign Management> Non deliverables and addresses.
Here you can then add the column for the "Delivery action" filter on the delivery internal name and get the addresses that were sent to the Quarantine list due to hard bounces.
Br,
Shubham