There are a number of laws regarding your mailbox, which helps keep your mail carrier safe and helps her do the job more quickly and easily. Mailboxes have to be placed at a height between 3.5 and 4 feet, from the surface of the ground, and they must be located somewhere where it is safe to access. Other laws, according to the state in which you live, may apply.
In order for mail to get to the correct person, you have to follow postal laws regarding addressing. For any size envelope or package, you must print or type your address (the return address) in the upper left-hand corner. Postage should be placed in the upper right-hand corner. The delivery address should be located near the center, parallel to the longest side of the envelope or package. For express mail, you must use a specific label that you can get for free from your local post office.
When sending a package, you must use tape that is at least 2 inches wide to reinforce all of the seams. You also cannot use cord, string, twine or rope, because these items can get caught in the machinery that processes the mail. In general, the outside of your package has to be smooth and clearly labeled, without any part that could get caught or torn.
Most hazardous materials cannot be mailed. The sender is required to know and follow these laws. Some of the materials restricted include fireworks, small arms ammunition and fuses. There are also tight restrictions on mailing switchblade knives, alcoholic beverages, firearms, toxic liquids or powders, motor vehicle master keys, locksmithing devices and controlled substances.
There are also strict regulations regarding the mailing of perishable materials. In general, most live birds, warm-blooded animals, reptiles, spiders and insects are non-mailable, while non-poisonous insects, day-old poultry, some adult birds, certain small animals and dried or refrigerated dead or parts of dead animals can be mailed under certain restrictions. There are also special requirements for mailing eggs, meat and other items that could potentially go bad while in the mail.