Electronic mail is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic (digital) version of, or counterpart to, mail, at a time when "mail" meant only physical mail. Email later became a ubiquitous communication medium, to the point that in current use, an e-mail address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries. Email is the medium, and each message sent therewith is called an email.
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 9051.
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. POP version 3 (POP3) is the version in common use, and along with IMAP the most common protocols for email retrieval.
The Simple Mail Transfer Protocol (SMTP) is an internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages. User-level email clients typically use SMTP only for sending messages to a mail server for relaying, and typically submit outgoing email to the mail server on port 587 or 465 per RFC 8314. For retrieving messages, IMAP is standard, but proprietary servers also often implement proprietary protocols, e.g., Exchange ActiveSync.
An email client, email reader or, more formally, message user agent (MUA) or mail user agent is a computer program used to access and manage a user's email.
Microsoft Outlook is a personal information manager software system from Microsoft, available as a part of the Microsoft Office suite. Though primarily an email client, Outlook also includes such functions as calendaring, task managing, contact managing, note-taking, journal logging and web browsing.
Microsoft Exchange Server is a mail server and calendaring server developed by Microsoft. It runs exclusively on Windows Server operating systems.
Pegasus Mail is a proprietary email client developed by David Harris. It was originally released in 1990 for internal and external mail on NetWare networks with MS-DOS and later Apple Macintosh clients. It was subsequently ported to Microsoft Windows, which is now the only platform actively supported. Previously freeware, Pegasus Mail is now donationware.
The Cyrus IMAP server is electronic mail server software developed by Carnegie Mellon University. It differs from other Internet Message Access Protocol (IMAP) server implementations in that it is generally intended to be run on sealed servers, where normal users cannot log in.
The UW IMAP server was the reference server implementation of the Internet Message Access Protocol. It was developed at the University of Washington by Mark Crispin and others.
Mulberry is an open-source email client marketed by Cyrusoft from approximately 1995 to 2005. On October 1, 2005, Cyrusoft International, Inc./ISAMET, declared Chapter 7 bankruptcy and went out of business. In August 2006, rights to the source code were acquired by Cyrus Daboo, the original author.
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 an email protocol designed as a faster way to synchronise a mobile device like a PDA or smartphone to an email server.
A mailbox is the destination to which electronic mail messages are delivered. It is the equivalent of a letter box in the postal system.
Windows Live Mail was a freeware email client from Microsoft. It is the successor to Windows Mail in Windows Vista, which was the successor to Outlook Express in Windows XP and Windows 98. Windows Live Mail is designed to run on Windows 7 and Windows Server 2008 R2, but is also compatible with Windows 8 and Windows 10, even though Microsoft bundles a new email client, named Windows Mail, with the latter.
GroupWise is a messaging and collaboration platform from Micro Focus that supports email, calendaring, personal information management, instant messaging, and document management. The GroupWise platform consists of desktop client software, which is available for Windows,, and the server software, which is supported on Windows Server and Linux.
A mailbox provider, mail service provider or, somewhat improperly, email service provider is a provider of email hosting. It implements email servers to send, receive, accept, and store email for other organizations or end users, on their behalf.
Mail is an email client developed by Microsoft and included in Windows Vista and later versions of Windows. It is available as the successor to Outlook Express, which was either included with, or released for Internet Explorer 3.0 and later versions of Internet Explorer.
The JSON Meta Application Protocol (JMAP) is a set of related open Internet Standard protocols for handling email. JMAP is implemented using JSON APIs over HTTP and has been developed as an alternative to IMAP/SMTP and proprietary email APIs such as Gmail and Outlook. Additional protocols and data models being built on top of the core of JMAP for handling contacts and calendar synchronization are meant to be potential replacements for CardDAV and CalDAV, and other support is currently in the works.
