This is how the Post Office works: The more work Precision Mailers does for them the cheaper we can get the postage, period. It costs .41 cents to mail a standard letter and .25 cents to mail a 4.25” x 6” postcard. Precision Mailers can get postage as cheap as .14 cents. We can do this by using our state of the art software to sort your list for the best possible discounts.