The NSW Supreme Court discussed the operation of s 160 of the Evidence Act 1995 (NSW) in Gabriel Hotels Pty Ltd v Corlita Pty Ltd  NSWSC 826.
That section is the same as our own s 160, and reads,
160. Postal articles
(1) It is presumed (unless evidence sufficient to raise doubt about the presumption is adduced) that a postal article sent by prepaid post addressed to a person at a specified address in Australia or in an external Territory was received at that address on the fourth working day after having been posted.
(2) This section does not apply if-
(a) the proceeding relates to a contract; and
(b) all the parties to the proceeding are parties to the contract; and
(c) subsection (1) is inconsistent with a term of the contract.
(3) In this section, working day means a day that is not-
(a) a Saturday or a Sunday; or
(b) a public holiday or a bank holiday in the place to which the postal article was addressed.
We discussed this section here last year. I said then that I thought that this presumption would be a very weak one, and Gabriel Hotels tends to shows this prediction to be correct.
A brochure from Australia Post setting out standard delivery timeframes was found to be sufficient to rebut the presumption in this case.