
You're sending important items that need to arrive in 1-3 business days. 1 You need date-certain delivery with a money-back guarantee. You're sending something urgent that must arrive next-day or 2-day. Go to the Post Office to ship heavier items like books and educational material. Mail, like postcards, letters in small envelopes (up to 3.5 oz), and large envelopes (up to 13 oz).


Review USPS Publication 52, Hazardous, Restricted, & Perishable MailĬompare All USPS Domestic Mail & Shipping Servicesįast air delivery for your most important mail and packages (with some Flat Rate options). See More Details: Domestic Shipping Prohibitions, Restrictions, & HAZMAT If you have any questions about what you may ship through USPS, review the restricted and prohibited items list. If you don’t follow the rules, you might face fines, or even criminal penalties. You have to follow all laws and USPS regulations. Some items have special packaging requirements, or can only be sent via ground transport, like perfumes containing alcohol.Perishable items (like plants or food) are generally OK to send as long as they are properly packaged and won’t spoil or leak.

