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Postmaster (computing)
In computers and technology, a postmaster is the administrator of a mail server. Nearly every domain should have the e-mail address [email protected] where errors in e-mail processing are directed. Error e-mails automatically generated by mail servers' MTAs usually appear to have been sent to the postmaster address. Every domain that supports the SMTP protocol for electronic mail is required by RFC 5321 and, as early as 1982, by RFC 822, to have the postmaster address. The rfc-ignorant.org website used to maintain a list of domains that do not comply with the RFC based on this requirement, but was shut down in November 2012. The websitRFC2 Realtime Listexpanded to include rfc-ignorant's lists after they shut down. Quoting from the RFC: Any system that includes an SMTP server supporting mail relaying or delivery MUST support the reserved mailbox "postmaster" as a case-insensitive local name. This postmaster address is not strictly necessary if the server always returns ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computers
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These programs enable computers to perform a wide range of tasks. A computer system is a nominally complete computer that includes the hardware, operating system (main software), and peripheral equipment needed and used for full operation. This term may also refer to a group of computers that are linked and function together, such as a computer network or computer cluster. A broad range of industrial and consumer products use computers as control systems. Simple special-purpose devices like microwave ovens and remote controls are included, as are factory devices like industrial robots and computer-aided design, as well as general-purpose devices like personal computers and mobile devices like smartphones. Computers power the Internet, which lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technology
Technology is the application of knowledge to reach practical goals in a specifiable and reproducible way. The word ''technology'' may also mean the product of such an endeavor. The use of technology is widely prevalent in medicine, science, industry, communication, transportation, and daily life. Technologies include physical objects like utensils or machines and intangible tools such as software. Many technological advancements have led to societal changes. The earliest known technology is the stone tool, used in the prehistoric era, followed by fire use, which contributed to the growth of the human brain and the development of language in the Ice Age. The invention of the wheel in the Bronze Age enabled wider travel and the creation of more complex machines. Recent technological developments, including the printing press, the telephone, and the Internet have lowered communication barriers and ushered in the knowledge economy. While technology contribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mail Server
Within the Internet email system, a message transfer agent (MTA), or mail transfer agent, or mail relay is software that transfers electronic mail messages from one computer to another using SMTP. The terms mail server, mail exchanger, and MX host are also used in some contexts. Messages exchanged across networks are passed between mail servers, including any attached data files (such as images, multimedia or documents). These servers also often keep mailboxes for email. Access to this email by end users is typically either via 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 adds a trace header field to the top of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E-mail Address
An email address identifies an email box to which messages are delivered. While early messaging systems used a variety of formats for addressing, today, email addresses follow a set of specific rules originally standardized by the Internet Engineering Task Force (IETF) in the 1980s, and updated by . The term email address in this article refers to just the ''addr-spec'' in Section 3.4 of RFC 5322. The RFC defines ''address'' more broadly as either a ''mailbox'' or ''group''. A ''mailbox'' value can be either a ''name-addr'', which contains a ''display-name'' and ''addr-spec'', or the more common ''addr-spec'' alone. An email address, such as ''[email protected]'', is made up from a local-part, the symbol @, and a ''domain'', which may be a domain name or an IP address enclosed in brackets. Although the standard requires the local part to be case-sensitive, it also urges that receiving hosts deliver messages in a case-independent manner, e.g., that the mail system in the domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Mail
Electronic mail (email or e-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 (hence '' e- + mail''). Email later became a ubiquitous (very widely used) communication medium, to the point that 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'' is the medium, and each message sent therewith is also called an ''email.'' The term is a mass noun. Email operates across computer networks, primarily the Internet, and also local area networks. Today's email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simulta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mail Transfer Agent
The mail or post is a system for physically transporting postcards, letters, and parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid-19th century, national postal systems have generally been established as a government monopoly, with a fee on the article prepaid. Proof of payment is usually in the form of an adhesive postage stamp, but a postage meter is also used for bulk mailing. With the advent of email, the retronym "snail mail" was coined. Postal authorities often have functions aside from transporting letters. In some countries, a postal, telegraph and telephone (PTT) service oversees the postal system, in addition to telephone and telegraph systems. Some countries' postal systems allow for savings accounts and handle applications for passports. The Universal Postal Union (UPU), established in 1874, includes 192 member countries and sets the rules for international mail exchanges as a Specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 587 or 465 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 (for plai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Case Sensitivity
In computers, case sensitivity defines whether uppercase and lowercase letters are treated as distinct (case-sensitive) or equivalent (case-insensitive). For instance, when users interested in learning about dogs search an e-book, "dog" and "Dog" are of the same significance to them. Thus, they request a case-insensitive search. But when they search an online encyclopedia for information about the United Nations, for example, or something with no ambiguity regarding capitalization and ambiguity between two or more terms cut down by capitalization, they may prefer a case-sensitive search. Areas of significance Case sensitivity may differ depending on the situation: * Searching: Users expect information retrieval systems to be able to have correct case sensitivity depending on the nature of an operation. Users looking for the word "dog" in an online journal probably do not wish to differentiate between "dog" or "Dog", as this is a writing distinction; the word should be matched wheth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E-mail Spam
Email spam, also referred to as junk email, spam mail, or simply spam, is unsolicited messages sent in bulk by email (spamming). The name comes from a Monty Python sketch in which the name of the canned pork product Spam is ubiquitous, unavoidable, and repetitive. Email spam has steadily grown since the early 1990s, and by 2014 was estimated to account for around 90% of total email traffic. Since the expense of the spam is borne mostly by the recipient, it is effectively postage due advertising. This makes it an excellent example of a negative externality. The legal definition and status of spam varies from one jurisdiction to another, but nowhere have laws and lawsuits been particularly successful in stemming spam. Most email spam messages are commercial in nature. Whether commercial or not, many are not only annoying as a form of attention theft, but also dangerous because they may contain links that lead to phishing web sites or sites that are hosting malware or include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bounce Message
A bounce message or just "bounce" is an automated message from an email system, informing the sender of a previous message that the message has not been delivered (or some other delivery problem occurred). The original message is said to have "bounced". This feedback may be immediate (some of the causes described here) or, if the sending system can retry, may arrive days later after these retries end. More formal terms for bounce message include "Non-Delivery Report" or "Non-Delivery Receipt" (NDR), ailed"Delivery Status Notification" (DSN) message, or a "Non-Delivery Notification" (NDN). Classification Although the SMTP is a mature technology, counting more than thirty years, the architecture is increasingly strained by both normal and unsolicited load. The email systems have been enhanced with reputation systems tied to the actual sender of the email, with the idea of recipient's email servers rejecting email when a forged sender is used in the protocol. Therefore, two type ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Return-path
{{No footnotes, date=June 2016 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 envelope in this analogy is the contents of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
