sorting office From WikiWord, the free dictionary English Contents DefinitionsRelated wordsReferences DefinitionsnounA building in which mail is collected together, then sorted prior to delivery. Related wordsSynonymsmailroompostroommailboxpost boxexpress officepigeonholeletterboxpost officereceiving housepost office boxbureauofficemail boxpacking roommail-boxoffice block References Wiktionary — sorting office Wikipedia — sorting office