Speed, cost, content, weight, and quantity are criteria used to determine the best method of mailing. Choosing the right service class can save money while meeting your objectives.

The following descriptions highlight key services for each Domestic Mail (not International) service class. Services are in cost and delivery speed order.  Remember, label each piece of mail with the appropriate service class before sending to Mail Services, with the exception of #10 or smaller First-Class letters and postcards.

Express Mail...

Is a guaranteed expedited postal service for shipping. It offers next-day delivery by noon to most destinations, second-day to remote areas. Express mail is delivered 365 days per year with no additional cost for weekend or holiday deliveries (if a business is closed, mail will be delivered the following business day). An Express Address Label is required. Special Express Envelopes are available, or an Express Address Label may be used on your own envelope or package. Maximum weight is 70 lbs. Postage rate is determined by item weight. Minimum postage fee is $14.40.

Priority Mail....

Is First-Class Mail weighing over 13 ounces. At your option, any mail weighing less than 13 ounces may also be mailed Priority. Priority Mail offers two or three day service to most locations. Special Priority Envelopes are available or Priority Labels may be used on your own envelope or package in conjunction with your own address label. Maximum weight is 70 lbs. Delivery zones and shipping weights determine the postage price. Minimum postage fee is $4.05 for up to 1 lb., and zone increases apply after 1 lb.

First-Class Mail...

Is the basic postal service mail class for business mail. Items normally mailed First-Class include postcards, letters, and non-letter mail that are personal in nature. This includes bills, invoices, checks, letters containing personalized information, and anything sealed against postal inspection. It is not necessary to identify service class on the piece. Delivery ranges from one to seven days depending on travel distance. Maximum weight is 13 oz. Minimum postage fee is $.24 for postcards, and $.39 for letters up to 1 oz.

Parcel Post...

Is generally used by businesses for shipping merchandise. Minimum weight is 1 lb., and maximum weight is 70 lbs. The maximum dimension is 130 inches in length and girth combined. Parcel Post has lower rates and slower travel time than Priority Mail. Delivery ranges from several days to two weeks depending on distance. Delivery zones and shipping weights determine the postage price. Please label items “Parcel Post.” Unlabeled parcels (not having service class noted on package) will be mailed at Parcel Post rate.

Media Mail...

Is generally used for books, films, printed music, printed test materials, sound recordings, manuscripts, printed educational charts, loose-leaf pages, and binders consisting of medical information, as well as computer readable media. Advertising restrictions apply. Minimum weight is 1 lb., maximum weight is 70 lbs. The maximum dimension is 108 inches in length and girth combined. Delivery ranges from several days to two weeks depending on distance. There is no delivery zone up-charge. Shipping weights determine the price. Please label items “Media Mail.”

Library Mail...

Is a special class rate, mailed between libraries, schools, universities, nonprofit organizations, and museums. Items that can be mailed at this rate include books, recordings, educational, and museum materials. This rate may be used when mailing from the University of Michigan to an individual who has no financial interest in the sale, promotion, or distribution of the materials. Advertising restrictions apply. Minimum weight is 1 lb., maximum weight is 70 lbs. The maximum dimension is 108 inches in length and girth combined. Delivery ranges from several days to two weeks depending on travel distance, and there is no delivery zone up-charge. Shipping weights determine the price. Please label items “Library Rate.”