I agree with the idea of not posting in the red boxes partly because of the heat as the top of the bags are open, and I have seen a posty wince when he touched an EXTREMELY hot ring on the bag, but also because items posted in them does not usually get scanned and therefore your tracking is usually not available.

I lodge everything at the post office and retain postage receipts whenever possible.

They also have a supply of  DO NOT SAFE DROP stickers to ensure your items do not just get left anywhere sorta close to the right address kinda,  if you sorta know what I kinda mean LIKE!!!

Some busy boxes get cleared during the day  but all boxes are cleared  AFTER 6pm. However many post offices have their internal lodgements collected as early as 3 pm, so you need to ask if an item is REALLY urgent if it can be posted in the box outside the post office.

I know that the Holden Hill post box outside the LPO is cleared at exactly 6.00pm as the driver waits until 6 to start his run there.

My old address at Pooraka was normally not cleared until 6.45 and today I was at Fulham gardens and the driver was waiting there until 6.01 pm.

While waiting at Lockleys this evening the one on Henley Beach Road at Lockleys was cleared about 6.25 which is about the time I normally see it get cleared.

It is handy to know regular times as there are occasions when I need to drop a box that is too large to fit the box so I wait  for the posty to arrive and hand him the parcel. Does not get full tracking but sometimes it can save it sitting in the post Office till Monday.