Email client

An email client (or MUA - mail user agent) is a program that receives mail from some source (a mailbox, such as a local message store, or a POP3 or IMAP server), processes it, and formats it for display to a user. An email client will also allow the user to send email messages via an outgoing mail (SMTP) server.

MUAs are distinct from MTAs (Mail Transfer Agents) such as sendmail or postfix because MTAs handle the actual work of dispatching email.

Most email clients include a standard set of features:
 * The ability to send and receive email from at least one account
 * An address book of commonly-used email addresses
 * Some sort of "filtering" ruleset for deleting useless or bothersome messages
 * Some sort of "cataloging" system (also known as "vfolders") for collecting related emails into categories or folders

Specific applications
Popular email clients for Linux and Unix include:
 * BALSA - a GNOME-based email reader
 * elm - an older, text-based email program
 * Evolution - a full-featured personal information manager that includes email
 * Kmail - a mail program for the KDE desktop
 * Mozilla - a powerful combination of web browser and email program
 * mutt - a newer, text-based email program
 * pine - Program for Internet News and Email (or Pine Is Not Elm)
 * Thunderbird - an easy-to-use email program complete with junk mail filtering

Webmail
Main article: Web-Mail


 * SquirrelMail
 * Horde
 * RoundCube
 * BlueMamba
 * IlohaMail
 * UebiMiau