A postal service clerk, also known as a mail handler, performs day-to-day tasks in a post office. In this career, your job duties include receiving and processing letters, parcels, and other mail and selling postage stamps, cards, and envelopes. Other duties include filling out money orders, weighing mail to find the cost, determining whether packages comply with federal laws and state regulations, sorting mail in the correct bags, obtaining correct postage and signatures for special deliveries. Customer service skills and experience in performing administrative or clerical tasks are vital in this career.