The government owned Australia Post increased its dividend this year to its sole shareholder from 60% of profits to 75%. This increase came about after a request from the government ministers. The details can be found in this transcript of the Environment, Communications, Information technology and the Arts Legislation Committee.
It would take more resources than I have but one could determine the amount of this profit earned at the cost to small businesses where Australia Post directly competes for stationery, greeting card and other business.