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Smart Host
A smart host or smarthost is an email server via which third parties can send emails and have them forwarded on to the email recipients' email servers. Smarthosts were originally open mail relays, but most providers now requiring authentication from the sender, to verify that the sender is authorised - for example, an ISP might run a smarthost for their paying customers only. Use in spam control efforts In an effort to reduce email spam originating from their customer's IP addresses, some internet service providers (ISPs), will not allow their customers to communicate out directly with recipient mailservers via the default SMTP port number 25. Instead, often they will set up a smarthost to which their customers can direct all their outward mail - or customers could alternatively use one of the commercial smarthost services. Sometimes, even if outward port 25 is not blocked, an individual or organisation's normal external IP address has difficulty getting SMTP mail accepted. This c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Message Transfer Agent
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 the he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Mail Relay
An open mail relay is a Simple Mail Transfer Protocol (SMTP) server configured in such a way that it allows anyone on the Internet to send e-mail through it, not just mail destined to or originating from known users. This used to be the default configuration in many mail servers; indeed, it was the way the Internet was initially set up, but open mail relays have become unpopular because of their exploitation by spammers and worms. Many relays were closed, or were placed on blacklists by other servers. History and technology Until the 1990s, mail servers were commonly intentionally configured as open relays; in fact, this was frequently the installation default setting. The traditional store and forward method of relaying e-mail to its destination required that it was passed from computer to computer (through and beyond the Internet) via modems on telephone lines. For many early networks, such as UUCPNET, FidoNet and BITNET, lists of machines that were open relays were a core par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Service Provider
An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise privately owned. Internet services typically provided by ISPs can include Internet access, Internet transit, domain name registration, web hosting, Usenet service, and colocation. An ISP typically serves as the access point or the gateway that provides a user access to everything available on the Internet. Such a network can also be called as an eyeball network. History The Internet (originally ARPAnet) was developed as a network between government research laboratories and participating departments of universities. Other companies and organizations joined by direct connection to the backbone, or by arrangements through other connected companies, sometimes using dialup tools such as UUCP. By the late 1980s, a process was set in place towa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Email 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 includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IP Address
An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface identification and location addressing. Internet Protocol version 4 (IPv4) defines an IP address as a 32-bit number. However, because of the growth of the Internet and the depletion of available IPv4 addresses, a new version of IP (IPv6), using 128 bits for the IP address, was standardized in 1998. IPv6 deployment has been ongoing since the mid-2000s. IP addresses are written and displayed in human-readable notations, such as in IPv4, and in IPv6. The size of the routing prefix of the address is designated in CIDR notation by suffixing the address with the number of significant bits, e.g., , which is equivalent to the historically used subnet mask . The IP address space is managed globally by the Internet Assigned Numbers Authority (IA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Service Provider
An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise privately owned. Internet services typically provided by ISPs can include Internet access, Internet transit, domain name registration, web hosting, Usenet service, and colocation. An ISP typically serves as the access point or the gateway that provides a user access to everything available on the Internet. Such a network can also be called as an eyeball network. History The Internet (originally ARPAnet) was developed as a network between government research laboratories and participating departments of universities. Other companies and organizations joined by direct connection to the backbone, or by arrangements through other connected companies, sometimes using dialup tools such as UUCP. By the late 1980s, a process was set in place towa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Port (computer Networking)
In computer networking, a port is a number assigned to uniquely identify a connection endpoint and to direct data to a specific service. At the software level, within an operating system, a port is a logical construct that identifies a specific process or a type of network service. A port is identified for each transport protocol and address combination by a 16-bit unsigned number, known as the port number. The most common transport protocols that use port numbers are the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). A port number is always associated with an IP address of a host and the type of transport protocol used for communication. It completes the destination or origination network address of a message. Specific port numbers are reserved to identify specific services so that an arriving packet can be easily forwarded to a running application. For this purpose, port numbers lower than 1024 identify the historically most commonly used services ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Mail Transfer Protocol
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 plaintext) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mail Submission Agent
A message submission agent (MSA), or mail submission agent, is a computer program or software agent that receives electronic mail messages from a mail user agent (MUA) and cooperates with a mail transfer agent (MTA) for delivery of the mail. It uses ESMTP, a variant of the Simple Mail Transfer Protocol (SMTP), as specified in RFC 6409. Many MTAs perform the function of an MSA as well, but there are also programs that are specially designed as MSAs without full MTA functionality. Historically, in Internet mail, both MTA and MSA functions use port number 25, but the official port for MSAs is 587. The MTA accepts a user's incoming mail, while the MSA accepts a user's outgoing mail. Benefits Separation of the MTA and MSA functions produces several benefits. One benefit is that an MSA, since it is interacting directly with the author's MUA, can correct minor errors in a message's format (such as a missing ''Date'', ''Message-ID'', ''To'' fields, or an address with a missing domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux Gazette
''The Linux Gazette'' was a monthly self-published Linux computing webzine, published between July 1995 and June 2011. Its content was published under the Open Publication License. History It was started in July 1995 by John M. Fisk as a free service. He went on to pursue his studies and become a medical doctor. At Mr. Fisk's request, the publication was sponsored and managed by SSC (Specialized System Consultants, who at that time were also publishers of Linux Journal). The content was always provided by volunteers, including most of the editorial oversight. After those years, the volunteer staff and the management of SSC had a schism (see Bifurcation below). Both the volunteer-run magazine and the magazine run by SSC has been closed down. One way Linux Gazette differed from other, similar, webzines (and magazines) was ''The Answer Gang''. In addition to providing a regular page devoted to questions and answers, questions to The Answer Gang were answered on a mailing list, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant university and the founding campus of the University of California system. Its fourteen colleges and schools offer over 350 degree programs and enroll some 31,800 undergraduate and 13,200 graduate students. Berkeley ranks among the world's top universities. A founding member of the Association of American Universities, Berkeley hosts many leading research institutes dedicated to science, engineering, and mathematics. The university founded and maintains close relationships with three national laboratories at Berkeley, Livermore and Los Alamos, and has played a prominent role in many scientific advances, from the Manhattan Project and the discovery of 16 chemical elements to breakthroughs in computer science and genomics. Berkeley is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dial-up Internet Access
Dial-up Internet access is a form of Internet access that uses the facilities of the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP) by dialing a telephone number on a conventional telephone line. Dial-up connections use modems to decode audio signals into data to send to a router or computer, and to encode signals from the latter two devices to send to another modem. History In 1979, Tom Truscott and Jim Ellis, graduates of Duke University, created an early predecessor to dial-up Internet access called the USENET. The USENET was a UNIX based system that used a dial-up connection to transfer data through telephone modems. Dial-up Internet has been around since the 1980s via public providers such as NSFNET-linked universities. The BBC established Internet access via Brunel University in the United Kingdom in 1989. Dial-up was first offered commercially in 1992 by Pipex in the United Kingdom and Sprint in the United Stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
