Third class mail, referred to by the United States Postal Service as Standard Mail, is a type of mail used by companies to send bulk mail to people throughout the country. The US Postal Service requires the company to perform some of the preparing and sorting of bulk mail in return for a reduced mailing rate. The USPS also charges an annual mail fee based on the number of standard mailings you will be making per year.

Requirements

In order to qualify, mailings must be at least 50 lbs. or 200 pieces of mail. The mail cannot weight more than 16 oz. or 1 lb. per piece. The mailing cannot include typewritten letters, handwritten letters or personal correspondence of any kind. For example, wedding invitations would not qualify at this rate because it is personal correspondence.

Enhanced Carrier Route

This type of standard rate refers to a bulk mailing that is done for a targeted mailing -- for example, a restaurant mailing to potential patrons in the immediate area. Rates are based on weight, shape and the size of each individual piece. Additionally, the mail must be presorted in the manner in which the carrier delivers the mail.

Non-Profit

Non-Profit Standard Mail needs to meet the same requirements as other bulk mailing. However, the rates for non-profit organizations is reduced. The USPS does not recognize every organization that meets IRS non-profit requirements. Organizations must fit into one of 10 categories defined on the official USPS website. Those categories include Agricultural, Educational, Fraternal, Labor, Philanthropic, Religious, Scientific, Veterans, Voter Registration Officials and National and State Political Parties.

Types of Mail

The USPS lists several types of mail that are used in bulk mailings. They include printed fliers, circulars and advertisements. Newsletters, bulletins, catalogs and small packages. Additional services such as Certified Mail for packages are available on bulk mailings for an additional fee.