I think you might find the delay with Aust Post is due to the severe bushfires. These fires are on an unbelievable scale in NSW right from the Qld boarder down to Sydney. It's very worrying times for a lot of people especially around us as the mega fire burning north west of Sydney is over 350,000 ha and he been reported unstoppable unless we get rain which is not due to late Jan early Feb.
Aust Post has got a notice on their website about the delays due to highway and road closures.