Email client
An email client, email reader, or more formally mail user agent (MUA), is a computer program used to access and manage a user’s email. The term can refer to any system capable of accessing the user’s email mailbox, regardless of it being a mail user agent, a relaying server, or a human typing on a terminal. In addition, a web application that provides message management, composition, and reception functions is sometimes also considered an email client, but more commonly referred to as webmail.