Mail Retrieval Agent
A mail retrieval agent (MRA) is a computer application that retrieves or fetches e-mail from a remote mail server and works with a mail delivery agent to deliver mail to a local or remote email mailbox. MRA is an automated agent that works on behalf of the user agent checks for the new incoming mail. MRAs may be external applications by themselves or be built into bigger applications like a mail user agent. Significant examples of standalone MRAs include fetchmail and getmail. The concept of an MRA is not standardized in email architecture. Although they operate like mail transfer agents, MRAs are technically clients when they retrieve and submit messages. Delivery mechanisms The mail retrieval agent may support delivery of retrieved mail via the following mechanisms: * Via a mail transport agent (Listening for SMTP transfers on port 25) * Via a mail delivery agent * Direct delivery to an mbox formatted mailbox * Direct delivery to a maildir directory * Output to standard outpu ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Computer
A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic sets of operations known as Computer program, ''programs'', which enable computers to perform a wide range of tasks. The term computer system may refer to a nominally complete computer that includes the Computer hardware, hardware, operating system, software, and peripheral equipment needed and used for full operation; or to a group of computers that are linked and function together, such as a computer network or computer cluster. A broad range of Programmable logic controller, industrial and Consumer electronics, consumer products use computers as control systems, including simple special-purpose devices like microwave ovens and remote controls, and factory devices like industrial robots. Computers are at the core of general-purpose devices ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Application (computer)
Application software is any computer program that is intended for end-user use not operating, administering or programming the computer. An application (app, application program, software application) is any program that can be categorized as application software. Common types of applications include word processor, media player and accounting software. The term ''application software'' refers to all applications collectively and can be used to differentiate from system and utility software. Applications may be bundled with the computer and its system software or published separately. Applications may be proprietary or open-source. The short term ''app'' (coined in 1981 or earlier) became popular with the 2008 introduction of the iOS App Store, to refer to applications for mobile devices such as smartphones and tablets. Later, with introduction of the Mac App Store (in 2010) and Windows Store (in 2011), the term was extended in popular use to include desktop applications. ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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E-mail
Electronic mail (usually shortened to email; alternatively hyphenated e-mail) is a method of transmitting and receiving Digital media, digital messages using electronics, electronic devices over a computer network. It was conceived in the late–20th century as the digital version of, or counterpart to, mail (hence ''wikt:e-#Etymology 2, e- + mail''). Email is a ubiquitous and very widely used communication medium; in current use, an email 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 operates across computer networks, primarily the Internet access, Internet, and also local area networks. Today's email systems are based on a store-and-forward model. Email Server (computing), servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need to connect, ty ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mail Delivery Agent
A message delivery agent (MDA), or mail delivery agent, is a computer software component that is responsible for the delivery of e-mail messages to a local recipient's mailbox. It is also called a local delivery agent (LDA). Within the Internet mail architecture, local message delivery is achieved through a process of handling messages from the message transfer agent, and storing mail into the recipient's environment (typically a mailbox). Spam filtering usually occurs at the MDA under modern email architectures. Implementation Many mail handling software products bundle multiple message delivery agents with the message transfer agent component, providing for site customization of the specifics of mail delivery to a user. Unix On Unix-like systems, procmail and maildrop are the most popular MDAs. The Local Mail Transfer Protocol (LMTP) is a protocol that is frequently implemented by network-aware MDAs. Invocation The mail delivery agent is generally not started f ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Email Mailbox
A mailboxISO/IEC 2382:2015 (also electronic mailbox, email box, email mailbox, e-mailbox) is the destination to which electronic mail messages are delivered. It is the equivalent of a letter box in the postal system. Definitions A mailbox is identified by an email address. However, not all email addresses correspond to a storage facility. The term ''pseudo-mailbox'' is sometimes used to refer to an address that does not correspond to a definitive mail store. Email forwarding may be applied to reach end recipients from such addresses. Electronic mailing lists and email aliases are typical examples. RFC 5321, defines an ''email address'' as a character string that identifies a user to whom mail will be sent or a location into which mail will be deposited. The term ''mailbox'' refers to that depository. In that sense, the terms ''mailbox'' and ''address'' can be used interchangeably. RFC 5322 defines a mailbox as follows: ''A mailbox receives mail. It is a 'conceptual entity' tha ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Email Client
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. A web application which provides message management, composition, and reception functions may act as a web email client, and a piece of computer hardware or software whose primary or most visible role is to work as an email client may also use the term. Retrieving messages from a mailbox Like most client programs, an email client is only active when a user runs it. The common arrangement is for an email user (the client) to make an arrangement with a remote Mail Transfer Agent (MTA) server for the receipt and storage of the client's emails. The MTA, using a suitable mail delivery agent (MDA), adds email messages to a client's storage as they arrive. The remote mail storage is referred to as the user's mailbox. The default setting on many Unix systems is for the mail server to store formatted messages in mbox, within the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Fetchmail
Fetchmail is an open-source software utility for POSIX-compliant operating systems which is used to retrieve e-mail from a remote POP3, IMAP, or ODMR mail server to the user's local system. It was developed from thpopclientprogram, written by Carl Harris. Its chief significance is perhaps that its author, Eric S. Raymond, used it as a model to discuss his theories of open-source software development in a widely read and influential essay on software development methodologies ''The Cathedral and the Bazaar''. Design By design, Fetchmail's only means of delivering messages is by submitting them to the local MTA/Message transfer agent or invoking a mail delivery agent like procmail, maildrop, or sendmail; delivering directly to mail folders such as maildir is not supported. It is a C program evolved by gradual mutation from an ancestor already written in C. Dan Bernstein, getmail creator Charles Cazabon and FreeBSD developer Terry Lambert, have criticized Fetchmail's design, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Getmail
getmail is a simple mail retrieval agent intended as a replacement for fetchmail, implemented in Python. It can retrieve mail from POP3, IMAP4, and ''Standard Dial-up POP3 Service'' servers, with or without SSL. It supports simple and domain (multidrop) mailboxes, mail filtering via any arbitrary program, and supports a wide variety of mail destination types, including mboxrd, maildir, and external arbitrary mail delivery agents. Unlike fetchmail, getmail's Python foundation makes it nearly immune to buffer overflow security holes. It also has a simpler configuration syntax than fetchmail, but supports fewer authentication protocols. The software can also function as a basic mail delivery agent. Getmail is free software and is licensed under the GNU General Public License version 2. It is written and maintained by Charles Cazabon. The original getmail software requires Python 2, which is no longer supported. A fork named getmail6, which is not from getmail's original autho ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mail Transfer Agent
Within the Internet email system, a message transfer agent (MTA), mail transfer agent, or mail relay is software that transfers electronic mail messages from one computer to another using the Simple Mail Transfer Protocol. In some contexts, the alternative names mail server, mail exchanger, or MX host are used to describe an MTA. Messages exchanged across networks are passed between mail servers, including any attached data files (such as images, multimedia, or documents). These servers often keep mailboxes for email. Access to this email by end users is typically either by webmail or an email client. Operation A message transfer agent receives mail from either another MTA, a mail submission agent (MSA), or a mail user agent (MUA). The transmission details are specified by the Simple Mail Transfer Protocol (SMTP). When a recipient mailbox of a message is not hosted locally, the message is relayed, that is, forwarded to another MTA. Every time an MTA receives an email message, i ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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SMTP
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 465 or 587 per . For retrieving messages, IMAP (which replaced the older POP3) is standard, but proprietary servers also often implement proprietary protocols, e.g., Exchange ActiveSync. SMTP's origins began in 1980, building on concepts implemented on the ARPANET since 1971. It has been updated, modified and extended multiple times. The protocol version in common use today has extensible structure with various extensions for authentication, encryption, binary data transfer, and internationalized email addresses. SMTP servers commonly use the Transmission Control Protocol on port number 25 (between ser ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mbox
Mbox is a generic term for a family of related file formats used for holding collections of email messages. It was first implemented in Research Unix, Fifth Edition Unix. All messages in an mbox mailbox are Concatenation, concatenated and stored as plain text in a single file. Each message starts with the four characters "From" followed by a space (the so-called "From_ line") and the sender's email address. RFC 4155 defines that a UTC timestamp follows after another separating space character. A format similar to mbox is the MH Message Handling System. Other systems, such as Microsoft Exchange Server and the Cyrus (imapd), Cyrus IMAP server, store mailboxes in centralized databases managed by the mail system and not directly accessible by individual users. The maildir mailbox format is often cited as an alternative to the mbox format for networked email storage systems. Mail storage protocols Unlike the Internet protocols used for the exchange of email, the format used for th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Maildir
The Maildir e-mail format is a common way of storing email messages on a file system, rather than in a database. Each message is assigned a Computer file, file with a unique name, and each mail folder is a file system directory containing these files. Maildir was designed by Daniel J. Bernstein circa 1995, with a major goal of eliminating the need for program code to handle file locking and unlocking through use of the local filesystem. Maildir design reflects the fact that the only operations valid for an email message is that it be created, deleted or have its status changed in some way. __TOC__ Specifications A Maildir directory (file systems), directory (often named Maildir) usually has three subdirectories named tmp, new, and cur. * The tmp subdirectory temporarily stores e-mail messages that are in the process of being delivered. This subdirectory may also store other kinds of temporary files. * The new subdirectory stores messages that have been delivered, but have no ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |