Australia Post has announced a profit before tax for HY19 of $154 million, down 36% year-on-year.Profit after tax was $118 million, down 45%.Domestic parcels revenue grew by 10%, up $147 million. Group parcels profit grew by $25 million to $127 million.Letter revenues are down 10% ($125 million), which reduced profit by $102 million in the half. Delivery costs continue to grow, despite Australia Post allocating more parcels to PDOs for street delivery. Half a million new delivery addresses have been added in the past three years, while letter volumes have declined by 800 million.Australia Post expects to make a modest full-year profit in FY19.