A post-box is a receptacle that is used for the collection and storage of letters and other mail items. It is mainly found on street corners or at designated locations and is operated by postal services. Other synonyms for post-box include letterbox, mailbox, post office box, drop box, and mail slot. The term letterbox is often used interchangeably with post-box, particularly in the UK. The term mailbox is commonly used in the US and Canada. A post office box is a similar container used for the storage of mail at a post office or other location. A drop box is a mailbox designed for the convenient dropping off of mail by the sender.