MUA
also: mail client, email client
MUA (Mail User Agent) is a client application that enables users to compose, send, and read email messages. It provides the interface between the user and the mail system.
A Mail User Agent is software that handles email at the user level. It connects to mail servers (typically via SMTP for sending and IMAP/POP3 for receiving) to manage your messages. Common examples include Thunderbird, Evolution, and Mutt.
In Linux systems, MUAs range from graphical applications like Thunderbird to terminal-based clients like Mutt or Alpine. They abstract away the complexity of SMTP and IMAP protocols, allowing users to focus on composing and organizing email.
For example, Mutt is a lightweight terminal MUA popular among Linux power users: mutt -f imaps://mail.example.com/INBOX connects directly to an IMAP server and displays your inbox.