If individuals want to automatically refuse foreign mail or block all mail from a specific sender, they must submit a written request to the USPS to withhold correspondence for up to two years.
1 liter = 33.8140226 US fluid ounces. 1 US fluid ounce = 0.0295735297 liters. Note that this is for fluid ounces, not dry ounces. A fluid ounce is a measure of volume, just like a liter is. A dry ounce is a measure of weight.
1 pint = 2 cups = 0.473 liters. 1 quart = 4 cups = 0.946 liters. 1 gallon = 16 cups = 4 quarts = 3.785 liters. (The old English fluid ounce was 28.4 ml and the UK gallon was 4.54 liters) 1 gallon = 3.785 liters.