Hi Hubert,
did you mean “Subscribers / Maintenance / General / Inactive since …”?
This function will move your subscribers just to another list – not delete it.
(1) Add a new list eg “Sloths”, (2) use the function above to move the lazys Subscribers to this list (3) go to the tab “Lists” (4) select the list and (5) click on “Delete erveryone in that list”. Important: like the button says, everyone on this list will be deleted.
Greetings