The United States Postal Service is a practical option to ship items. However, there are restrictions on what objects you can send through the US Postal Service. This is part of the USPS' precautionary measures to prevent hazardous or dangerous materials from entering the mail system. Here is a list of what you can or cannot ship via the USPS.
There are no restrictions on mailing paper items such as personal letters, financial records, post cards, contracts and other documents. You can also send money via the US Postal Service but you cannot insure cash, stocks or bonds. The USPS recommends that if you need to mail money, send a personal check, money order or cashier's check so that if it got lost or stolen, you can report these items to your bank and receive your money back.
Personal items like clothing, pictures, media such as DVDs and CDs, jewelry, souvenirs, toys and books are also easy to mail via USPS. It would be best to purchase insurance when shipping expensive items as the postal service will pay the value of the insurance if it loses your package or damages the goods inside it.
The USPS sets a limit on the size or quantity you can mail for some items such as aerosol cans, firearms, tobacco products, liquids, poisons, flammable goods and lottery tickets. Go to a U.S. postal service office to ensure you do not exceed the restrictions. As of 2011, The USPS does not allow mailing packages weighing over 70 pounds, regardless of the item.
The US Postal Service' Prohibited Items list include drug paraphernalia, alcohol, weapon ammunition or small explosive devices such as fireworks. You cannot mail any hazardous items including anything that could rupture in transit and damage property or harm people. For example, you cannot ship corrosives such as lye or acids, toxic substances such as herbicides or flammable liquid such as acetone. Packages containing dry ice are prohibited so do not use dry ice when shipping food items.