Message Transfer Agents
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Message Transfer Agents
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, it ...
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Email
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 ...
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Email Box
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 ...
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Internet Mail Protocols
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a network of networks that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries a vast range of information resources and services, such as the interlinked hypertext documents and applications of the World Wide Web (WWW), electronic mail, internet telephony, streaming media and file sharing. The origins of the Internet date back to research that enabled the time-sharing of computer resources, the development of packet switching in the 1960s and the design of computer networks for data communication. The set of rules (communication protocols) to enable internetworking on the Internet arose from research and development commissioned in the ...
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Relay (other)
A relay is an electric switch operated by a signal in one circuit to control another circuit. Relay may also refer to: Electrical engineering * Protective relay, a device designed to trip a circuit breaker when a fault is detected. Historical * Stage station, a place where exhausted horses being used for transport could be exchanged for fresh ones * Cursus publicus, a courier service in the Roman Empire * Relay league, a chain of message-forwarding stations Computer networking * BITNET Relay, a 1980s online chat system * Mail relay, a server used for forwarding e-mail ** Open mail relay, such a server that can be used by anyone Other telecommunication * Relay (satellite) * Broadcast relay station, a transmitter which repeats or transponds the signal of another * Microwave radio relay * Relay channel, in information theory, a communications probability modeling system * Telecommunications Relay Service, a telephone accessibility service for the deaf * Repeater, an electro ...
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List Of Mail Server Software
This is a list of mail server software: mail transfer agents, mail delivery agents, and other computer software which provide e-mail. Product statistics All such figures are necessarily estimates because data about mail server share is difficult to obtain; there are few reliable primary sources—and no agreed methodologies for its collection. Surveys probing Internet-exposed systems typically attempt to identify systems via their banner, or other identifying features. , Postfix and exim appeared to be the overwhelming leaders in mail server types, with greater than 92% share between them, having come to prominence before 2010 in each case. While such methods are effective at identifying mail server share for receiving systems, most large-scale sending environments are not listening for traffic on the public internet and will not be counted using such methodologies. SMTP POP/IMAP JMAP Mail filtering Mail server packages See also * Comparison of mail servers ...
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Anti-Spam Research Group
The Anti-Spam Research Group (ASRG) was a research group started within the Internet Research Task Force (IRTF), where its charter concluded on 18 March 2013. It is still a reference and a melting pot for anti-spam research and theorization. In particular, the wiki lives on. Dedicated to research into curbing spam on an Internet-wide level, it consists of a mailing list to coordinate work and a small web site with a wiki. As with other IRTF groups, the ASRG contributed to the Internet Engineering Task Force (IETF) process with drafts, documents, and assistance in the creation of new working groups. One IETF group spun off from the ASRG is MARID. The ASRG is sporadically active, as little evolves in the anti-spam landscape, with most activity happening on the mailing list. In 2008 the ASRG worked on Internet Drafts about DNSBL A Domain Name System blocklist, Domain Name System-based blackhole list, Domain Name System blacklist (DNSBL) or real-time blackhole list (RBL) is a s ...
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Spam (electronic)
Spamming is the use of messaging systems to send multiple unsolicited messages (spam) to large numbers of recipients for the purpose of commercial advertising, non-commercial proselytizing, or any prohibited purpose (especially phishing), or simply repeatedly sending the same message to the same user. While the most widely recognized form of spam is email spam, the term is applied to similar abuses in other media: messaging spam, instant messaging spam, Newsgroup spam, Usenet newsgroup spam, spamdexing, Web search engine spam, spam in blogs, wiki spam, classified advertising, online classified ads spam, mobile phone spam, mobile phone messaging spam, Forum spam, Internet forum spam, junk fax, junk fax transmissions, social spam, spam mobile apps, television advertising and file sharing spam. It is named after Spam (food), Spam, a luncheon meat, by way of a Spam (Monty Python sketch), Monty Python sketch about a restaurant that has Spam in almost every dish in which Vikings annoyi ...
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MAPI
Messaging Application Programming Interface (MAPI) is an Application programming interface, API for Microsoft Windows which allows programs to become email-aware. While MAPI is designed to be independent of the protocol, it is usually used to communicate with Microsoft Exchange Server. Details MAPI uses functions loosely based on the X.400 XAPIA standard. It includes facilities to access Mail transfer agent, message transports, message stores, and Directory services, directories. While ''Simple MAPI'' (SMAPI) is a subset of 12 functions which enable developers to add basic messaging functionality, ''Extended MAPI'' (EMAPI) allows complete control over the messaging system on the client computer. This includes creation and management of messages, plus management of the client mailbox, and service providers. Simple MAPI is included with Microsoft Windows as part of Outlook Express/Windows Mail while the full Extended MAPI is included with Microsoft Outlook and Microsoft Exchan ...
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Internet Message Access Protocol
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 . IMAP was designed with the goal of permitting complete management of an email box by multiple email clients, therefore clients generally leave messages on the server until the user explicitly deletes them. An IMAP server typically listens on port number 143. IMAP over SSL/TLS (IMAPS) is assigned the port number 993. Virtually all modern e-mail clients and servers support IMAP, which along with the earlier POP3 (Post Office Protocol) are the two most prevalent standard protocols for email retrieval. Many webmail service providers such as Gmail and Outlook.com also provide support for both IMAP and POP3. Email protocols The Internet Message Access Protocol is an application layer Internet protocol that allows an e-mail client to access email on a remote mail server. The cu ...
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Post Office Protocol
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. Today, POP version 3 (POP3) is the most commonly used version. Together with IMAP, it is one of the most common protocols for email retrieval. Purpose The Post Office Protocol provides access via an Internet Protocol (IP) network for a user client application to a mailbox (''maildrop'') maintained on a mail server. The protocol supports list, retrieve and delete operations for messages. POP3 clients connect, retrieve all messages, store them on the client computer, and finally delete them from the server. This design of POP and its procedures was driven by the need of users having only temporary Internet connections, such as dial-up access, allowing these users to retrieve e-mail when connected, and subsequently to view and manipulate the retrieved messages when offline. POP3 clients also have an option to leave mail ...
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Return Path
{{Redir, Return path, the term in electronics, Return path (electronics) A bounce address is an email address to which bounce messages are delivered. There are many variants of the name, none of them used universally, including return path, reverse path, envelope from, envelope sender, MAIL FROM, 5321-FROM, return address, From_, Errors-to, etc. It is not uncommon for a single document to use several of these names. All of these names refer to the email address provided with the MAIL FROM command during the SMTP session. Background information Ordinarily, the bounce address is not seen by email users and, without standardization of the name, it may cause confusion. If an email message is thought of as resembling a traditional paper letter in an envelope, then the "header fields", such as To:, From:, and Subject:, along with the body of the message are analogous to the letterhead and body of a letter - and are normally all presented and visible to the user. However, the envel ...
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Software
Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital computers in the mid-20th century. Early programs were written in the machine language specific to the hardware. The introduction of high-level programming languages in 1958 allowed for more human-readable instructions, making software development easier and more portable across different computer architectures. Software in a programming language is run through a compiler or Interpreter (computing), interpreter to execution (computing), execute on the architecture's hardware. Over time, software has become complex, owing to developments in Computer network, networking, operating systems, and databases. Software can generally be categorized into two main types: # operating systems, which manage hardware resources and provide services for applicat ...
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