Mail clerks sort, distribute, and prepare mail for offices or customers.

Mail clerks sort and deliver internal mail, such as memos and bulletins, as well as incoming mail. Mail clerks also prepare outgoing mail for delivery to the post office.

Depending on the organization, mail clerks may send out advertising, customer orders, or legal documents. Clerks also decide what type of mail service to use. For example, they may choose registered mail for an important letter, or third class for bulk mail.

Mail clerks use various machines to prepare outgoing mail. They operate machines that collate, fold, and insert print material into envelopes. They may operate addressing machines or use computers to make address labels. They operate postage machines and may sort large mailings by zip code. During these processes, mail clerks observe the operation of the equipment to be sure it works properly. They adjust machines and inspect the prepared mail for any errors.

Clerks also stack bundles of bulk mail for shipment and load it into trucks. In addition, they keep records of incoming and outgoing mail.

Some mail clerks work for private mailing services. These clerks deal directly with customers. When they receive letters or packages to be mailed, they inspect them to be sure they meet requirements. They weigh letters or packages and compute mailing costs. In addition, these clerks answer customers' questions about shipping and mailing policies.