In message , NY writes

Does the Post Office actually act as a "virtual branch" of all the
various banks, or do you have to create and account with them and
transfer money into it from your bank account?

I may be a little out of date, as I retired as local postmaster 6 years
ago, but then, almost any debit card, including some foreign ones, could
be used to withdraw cash at any PO counter, without fee. Cash could
also be paid in.

Regarding cheques, yes, they go in an envelope to the bank overnight,
usually quicker than ordinary post, no cost (stamp) to the user and a
receipt as 'proof of posting' or proof that a cheque has been deposited,
although amount not shown, and the receipt just shows an envelope, not
how many cheques were inside. The system worked well, with very few
going missing, but when an envelope did go missing, it could take a
while to get sorted.

--
Graeme