I don't understand the admin part (either) but without that admin-vacation rpm, I have vacation working and on the manager panel (or at least it works for me using "-j" with 4.12, something in the header or alias match blocks replies otherwise; also I use "-n" with .vacation.msg symbolically linked to a file accessible to the user, the effect of which is to turn vacation on or off by the existence of that linked file (containing the reply text) not very elegant but works for now)