"Letter drops" also known as "mailboxes" are the receptacles used for collecting outgoing mail. Synonyms for "letter drops" include "post boxes", "mail slots", "post office boxes", and "letter boxes". These synonyms are often used interchangeably depending on the country or region in which they are used. For example, "post office box" is commonly used in the United States while "letter box" is often used in the United Kingdom. Regardless of the terminology used, these mail collection points remain an essential part of postal service infrastructure, allowing for the convenient and efficient transfer of mail from sender to recipient.