The Internet Protocol (IP) is the principal communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
In computer networking, the User Datagram Protocol (UDP) is one of the core members of the Internet protocol suite. The protocol was designed by David P. Reed in 1980 and formally defined in RFC 768. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol (IP) network. Prior communications are not required in order to set up communication channels or data paths.
A mail exchanger record specifies the mail server responsible for accepting email messages on behalf of a domain name. It is a resource record in the Domain Name System (DNS). It is possible to configure several MX records, typically pointing to an array of mail servers for load balancing and redundancy.
UUCP is an abbreviation of Unix-to-Unix Copy. The term generally refers to a suite of computer programs and protocols allowing remote execution of commands and transfer of files, email and netnews between computers.
An email address identifies an email box to which email messages are delivered. A wide variety of formats were used in early email systems, but only a single format is used today, following the standards developed for Internet mail systems since the 1980s. This article uses the term email address to refer to the addr-spec defined in RFC 5322, not to the address that is commonly used; the difference is that an address may contain a display name, a comment, or both.
The Local Mail Transfer Protocol (LMTP) is a derivative of ESMTP, the extension of the Simple Mail Transfer Protocol (SMTP). It is defined in RFC 2033. LMTP is designed as an alternative to normal SMTP for situations where the receiving side does not have a mail queue, such as a mail storage server acting as a Mail Delivery Agent (MDA).
Sender Policy Framework (SPF) is an email authentication method designed to detect forged sender addresses in emails, a technique often used in phishing and email spam.
Greylisting is a method of defending e-mail users against spam. A mail transfer agent (MTA) using greylisting will "temporarily reject" any email from a sender it does not recognize. If the mail is legitimate, the originating server will try again after a delay, and if sufficient time has elapsed, the email will be accepted.
Extended SMTP (ESMTP), sometimes referred to as Enhanced SMTP, is a definition of protocol extensions to the Simple Mail Transfer Protocol (SMTP) standard. ESMTP was defined in November 1995 in IETF publication RFC 1869 which established a general structure for all existing and future extensions.
Milter is an extension to the widely used open source mail transfer agents (MTA) Sendmail and Postfix. It allows administrators to add mail filters for filtering spam or viruses in the mail-processing chain. In the language of the art, "milter" refers to the protocol and API implementing the service, while "a milter" has come to refer to a filter application that uses milter to provide service.
lwIP is a widely used open-source TCP/IP stack designed for embedded systems. lwIP was originally developed by Adam Dunkels at the Swedish Institute of Computer Science and is now developed and maintained by a worldwide network of developers.
This is a comparison of mail servers: mail transfer agents, mail delivery agents, and other computer software that provide e-mail services.
Keith Moore is the author and co-author of several IETF RFCs related to the MIME and SMTP protocols for electronic mail, among others:
In computer networking, a port is an endpoint of communication. Physical as well as wireless connections are terminated at ports of hardware devices. 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. Ports are identified for each protocol and address combination by 16-bit unsigned numbers, commonly known as the port number. Inbound packets are received, and the port number in the header is used to decide which application is to be passed the packets.
ClearOS is an operating system marketed by the software company ClearCenter. It is based on CentOS and Red Hat Enterprise Linux, designed for use in small and medium enterprises as a network gateway and network server with a web-based administration interface. It is positioned as an alternative to Windows Small Business Server. ClearOS succeeds ClarkConnect. The software is built by ClearFoundation, and support services can be purchased from ClearCenter. ClearOS 5.1 removes previous limitations to mail, DMZ, and MultiWAN functions.
Amavis is an open-source content filter for electronic mail, implementing mail message transfer, decoding, some processing and checking, and interfacing with external content filters to provide protection against spam and viruses and other malware. It can be considered an interface between a mailer and one or more content filters.
DNS-based Authentication of Named Entities (DANE) is an Internet security protocol to allow X.509 digital certificates, commonly used for Transport Layer Security (TLS), to be bound to domain names using Domain Name System Security Extensions (DNSSEC).
Zentyal is an open source email and groupware solution based on Ubuntu Linux.
