Update:

Decided to call the post office, and asked re: collecting our own post.

It is up to the delivery office in question (mine is Perry Vale), so you have to phone them.

Number is 08456 112450, and you need option '4'. BUT our 'hard working' posties are only there until 1pm Monday-Friday, and until 12 Saturday, even in these strange times, so won't be able to get the answer to my question (or do anything about it) until tomorrow morning.

And who said email is killing the post service? They seem to be doing a great job by themselves.