Prepare incoming and outgoing mail for distribution. Examine, sort, and route mail by State, type of mail, or other scheme. Load, operate, and occasionally adjust and repair mail processing, sorting, and canceling machinery. Keep records of shipments, pouches, and sacks; and other duties related to mail handling within the postal service. Must complete a competitive exam.

Other names for Postal Service Mail Sorters, Processors, and Processing Machine Operators: Assorter, Automation Clerk, Computer Forwarding System Markup Clerk (CFS Markup Clerk), Data Conversion Operator, Dead Mail Checker, Distribution Clerk, Distributor, Equipment Operator, Flat Sorter Operator, Flat Sorting Machine Clerk (FSM Clerk), Letter Sorting Machine Operator (LSM Operator), Mail Distribution Scheme Examiner, Mail Distributor, Mail Handler, Mail Handler Sorter, Mail Opener, Mail Processing, Mail Processor, Mail Sorter, Mail Weigher, Mailing Section Clerk, Parcel Post Distribution Machine Operator (PDPMO), Postal Clerk, Postal Transportation Clerk, Registry Clerk, Small Package and Bundle Sorter Clerk (SPBS Clerk), Sorter, Sorting Machine Operator, Window Clerk, ZMT Operator (Zip Mail Translator Operator),

• Move containers of mail, using equipment such as forklifts and automated "trains."
• Sort odd-sized mail by hand, sort mail that other workers have been unable to sort, and segregate items requiring special handling.
• Accept and check containers of mail from large volume mailers, couriers, and contractors.
• Load and unload mail trucks, sometimes lifting containers of mail onto equipment that transports items to sorting stations.
• Cancel letter or parcel post stamps by hand.
• Dump sacks of mail onto conveyors for culling and sorting.
• Serve the public at counters or windows, such as by selling stamps and weighing parcels.
• Supervise other mail sorters.
• Train new workers.
• Distribute incoming mail into the correct boxes or pigeonholes.
• Operate various types of equipment, such as computer scanning equipment, addressographs, mimeographs, optical character readers, and bar-code sorters.
• Search directories to find correct addresses for redirected mail.
• Clear jams in sorting equipment.
• Check items to ensure that addresses are legible and correct, that sufficient postage has been paid or the appropriate documentation is attached, and that items are in a suitable condition for processing.
• Open and label mail containers.
• Rewrap soiled or broken parcels.
• Weigh articles to determine required postage.
• Direct items according to established routing schemes, using computer controlled keyboards or voice recognition equipment.
• Bundle, label, and route sorted mail to designated areas depending on destinations and according to established procedures and deadlines.