Preheat oven to 170 degrees C. Grease a ring tin and line with baking paper. Grease the baking paper. Sift flour, salt and baking powder together and set aside.
In a large bowl, cream butter, margarine and 3 cups sugar until light and fluffy. Add eggs one at a time, beating well after each. Add 1 teaspoon rum essence and 1 teaspoon coconut essence. Add flour mixture alternately with milk and evaporated milk. Mix until smooth.
Pour batter into ring tin. Bake for 1 hour and 15 minutes, or until a skewer inserted into cake comes out clean. Cool.
Make the glaze: in a saucepan, combine 1 cup sugar, 1/2 cup water, 1 teaspoon rum essence, 1 teaspoon coconut essence and 1 teaspoon almond essence. Bring to a boil, stirring constantly. Use a toothpick to pierce all over the top of the cake. Pour the glaze over the cooled cake and allow it to soak in.