In computing, the Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by RFC 3501.
In computing, the Post Office Protocol (POP) is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server.
The Simple Mail Transfer Protocol (SMTP) is a communication protocol for electronic mail transmission. As an Internet standard, SMTP was first defined in 1982 by RFC 821, and updated in 2008 by RFC 5321 to Extended SMTP additions, which is the protocol variety in widespread use today. Mail servers and other message transfer agents use SMTP to send and receive mail messages. Proprietary systems such as Microsoft Exchange and IBM Notes and webmail systems such as Outlook.com, Gmail and Yahoo! Mail may use non-standard protocols internally, but all use SMTP when sending to or receiving email from outside their own systems. SMTP servers commonly use the Transmission Control Protocol on port number 25.
Mail is an email client included by Apple Inc. with its operating systems macOS, iOS and watchOS. Mail grew out of NeXTMail, which was originally developed by NeXT as part of its NeXTSTEP operating system, after Apple's acquisition of NeXT in 1997.
Mutt is a text-based email client for Unix-like systems. It was originally written by Michael Elkins in 1995 and released under the GNU General Public License version 2 or any later version.
The Bat! is a shareware email client for the Microsoft Windows operating system, developed by Ritlabs, SRL, a company based in Chişinău, Moldova. There are two versions: a Home version and a Professional version. The Professional version includes a portable module, The Bat Voyager.
SquirrelMail is a project that provides both a web-based email client and a proxy server for the IMAP protocol.
Kontact is a personal information manager and groupware software suite developed by KDE. It supports calendars, contacts, notes, to-do lists, news, and email. It offers a number of inter-changeable graphical UIs all built on top of a common core.
The following tables compare general and technical features of a number of notable email client programs.
Dovecot is an open-source IMAP and POP3 server for Linux/UNIX-like systems, written primarily with security in mind. Timo Sirainen originated Dovecot and first released it in July 2002. Dovecot developers primarily aim to produce a lightweight, fast and easy-to-set-up open-source mailserver.
Roundcube is a web-based IMAP email client. Roundcube's most prominent feature is the pervasive use of Ajax technology. After about two years of development, the first stable release of Roundcube was announced in early 2008.
Push email is an email system that provides an always-on capability, in which new email is actively transferred (pushed) as it arrives by the mail delivery agent (MDA) to the mail user agent (MUA), also called the email client. Email clients include smartphones and, less strictly, IMAP personal computer mail applications.
The following tables compare general and technical information for a number of notable webmail providers who offer a web interface in English.
Push-IMAP, which is otherwise known as P-IMAP or Push extensions for Internet Message Access Protocol, is a email protocol designed as a faster way to synchronise a mobile device like a PDA or smartphone to an email server.
The Lemonade Profile is a set of protocols and mandatory extensions which provides email access to diverse environments, including mobile handsets and other resource constrained devices. It is the product of an IETF Working Group, and is largely based on pre-existing specifications, including IMAP and the Message Submission profile of SMTP. It was first published in 2006 as RFC 4550, and updated in 2009 as RFC 5550.
In email technology, IDLE is an IMAP feature described in RFC 2177 that allows a client to indicate to the server that it is ready to accept real-time notifications.
EmailTray is a lightweight email client for the Microsoft Windows operating system. EmailTray was developed by Internet Promotion Agency S.A., a software development company.
Geary is a free and open-source email client written in Vala and based on WebKitGTK. Although since adopted by the GNOME project, it originally was developed by the Yorba Foundation. The purpose of this e-mail client, according to Adam Dingle, Yorba founder, was to bring back users from online webmails to a faster and easier to use desktop application.
