I have emailed eBay a few times about the huge Postage Time misunderstanding for buyers. I suggested eBay put a little pop up there that tells them exactly how to judge what star ratings on postage time in relation to sellers NOT Australia Post. It's actually quite confusing the way it is.

Now I send my buyers an email after I have posted their parcels telling them what day & time I posted their parcel and tell them what delivery date Australia Post has nominated. I then explain to them that now Australia Post has their parcel I no longer have any control over its delivery time. The problem seems to have sorted itself out so far anyway. I know it's very time consuming but while it's working I'll do it.