SIMPLE TRANSFER PROTOCOL Иванов В.В.1, Черкасов Д.Ю.2 1Иванов Вадим Вадимович – студент института кибернетики, Российский Технологический Университет (Московский Институт Радиотехники Электроники и Автоматики) 2Черкасов Денис Юрьевич – студент института кибернетики, Российский Технологический Университет (Московский Институт Радиотехники Электроники и Автоматики) г. Москва, Российская Федерация Аннотация: SMTP является протоколом для передачи электронной почты. В отличие от стандартного POP3, данный сервер ориентирован преимущественно на передачу, хотя имеется возможность и получения письма по определенному адресу в рамках протокола. SMTP широко применяется большинством современных почтовых сервисов. Ключевые слова: SMTP, почта, протокол, сервер, информация. SIMPLE MAIL TRANSFER PROTOCOL Ivanov V.V.1, Cherkasov D.Y.2 1Ivanov Vadim Vadimovich– student of the Institute of Cybernetics, Russian Technological University (Moscow Institute of Engineering of Electronics and Automation) 2Cherkasov Denis Yurievich– student of the Institute of Cybernetics, Russian Technological University (Moscow Institute of Radio Engineering of Electronics and Automation) Moscow, Russian Federation Annotation: SMTP server is a protocol for sending e-mail. Unlike standard POP3, this server is oriented mainly to the transfer, although it is possible to receive a letter to a certain address within the protocol. SMTP is widely used by most modern mail services. Key words: SMTP, mail, protocol, server, information.. УДК 004

Электронный журнал «Столица Науки» СЕНТЯБРЬ 2(2) SMTP (Simple Mail Transfer Protocol) is a widely used network protocol for sending e-mail on TCP / IP networks. While e-mail servers and other messaging agents use SMTP to send and receive e-mail messages, user-level mail client applications typically use SMTP only to send messages to the mail server for relaying. To receive messages, client applications typically use either POP (), or IMAP ( Message Access Protocol), or proprietary systems (such as Microsoft Exchange and Lotus Notes / Domino) to access the accounting write your on the server. In the 1960s, various types of electronic communication were used. People connected with each other using systems designed for certain mainframes. When more and more became connected, especially in the US Government network, ARPANET, standards were developed to allow users on different systems to write electronic messages to each other. These standards, developed in the 1970s, became the basis for SMTP. Further implementations include FTP Mail and Mail Protocol, developed in 1973. Development continued throughout the 1970s until ARPANET was transformed into a modern Internet around 1980. In the same year, John Postel proposed the Mail Transport Protocol, , through which FTP has ceased to be the basis for the transfer of mail. SMTP is published in RFC 821 (also written by Postel) in August 1982. The SMTP standard was developed around the same time as , a data network that has some similarities with SMTP. SMTP became widely used in the early 1980s. At that time, it was a complement to Unix to Unix CoPy (UUCP), which was more suitable for processing the transfer of electronic messages between periodically connected devices. On the other hand, SMTP works fine when both sending and receiving devices are connected on the network all the time. Both devices use the storage and forwarding mechanism and are an example of push-technology (pushing technology). Although the Usenet newsgroups are still distributed between the servers using UUCP, the UUCP mail actually disappeared along with the "bang path" route (the host machine sequence on the network that the message should reach the destination) that were used as the headers. The article about rewriting the

Электронный журнал «Столица Науки» СЕНТЯБРЬ 2(2) contains technical background information on the history of early SMTP and routing from source to RFC 1123. was one of the first (if not the first) message forwarding agent in which SMTP was implemented. Other popular server programs supporting SMTP include , , Novell GroupWise, , Novell NetMail, Microsoft Exchange Server, Sun Java System Messaging Server. The provision of messages (RFC 2476) and SMTP-AUTH (RFC 2554) were introduced in 1998 and 1999. and described new trends in the transmission of electronic messages. Initially, SMTP servers were usually internal to the organization, receiving messages from organizations from outside and relaying the organization's messages to the external environment. But over time, SMTP servers (messaging agents), in fact, expanded their functions and eventually became messaging agents for custom applications, some of which now relayed mail from outside the organization (for example, the company manager, while on a trip , wants to send an e-mail message using a corporate SMTP server) [1]. This issue, being a consequence of the rapid development and popularity of the , means that SMTP should have included special rules and methods for relaying messages and authorizing users to prevent abuses such as junk mail (spam) relaying [2]. Since this protocol was initially with a text (ASCII) interface, it did not work well with binary files and symbols of many non-English languages. Standards such as Multipurpose Internet Mail Extensions (MIME) have been developed to encode binary files for transmission over SMTP. Sendmail agents developed after Sendmail, as a rule, also implemented the option of pure 8 bits, so that the "just send eight" alternative strategy can be used to transfer arbitrary text data (in any eight-bit ASCII-like character encoding) via SMTP. However, there was still the problem of krakozabr [en], caused by the different display of character sets from manufacturers, although the mail addresses themselves still allowed to use exclusively ASCII. Today, transfer agents that work with clean 8 bits tend to support the 8BITMIME extension, which allows the transfer of binary files almost as easily as plain text. Recently, an SMTPUTF8

Электронный журнал «Столица Науки» СЕНТЯБРЬ 2(2) extension was created to support UTF-8 encoded text, which made it possible to include international content and addresses using alphabets such as Cyrillic or Chinese. Many outstanding people have contributed to the specification of the main SMTP, including John Postel, Eric Ollman, Dave Crocker, Ned Fried, Randall Gellens, John Clensin and Keith Moore. SMTP function is implemented in modern TCP / IP networks. For the first time information about the use of the protocol appeared in 1982. Despite the fact that the SMTP server can be used for receiving messages, today most mail clients use it only for sending, preferring other technologies (for example, POP or IMAP) to receive information. The protocol is one of the most popular and is used by an overwhelming number of mail programs and servers. The function of SMTP is to check the correctness of the settings and parameters for sending a message. This protocol verifies the settings of the user's trying to send messages, and then the delivery is performed, if all the settings were performed correctly. After that, the SMTP operation does not end and the server waits for a message on the successful delivery of the data. If the message can not be delivered for some reason, a corresponding message is sent to the sender. SMTP setup The SMTP setup consists of installing the necessary software and determining the address of the server used for sending. To send from the user's side, it is required to install a client program that can send messages and communicate with the SMTP server via TCP / IP. After that, the program is launched and configured to work with the service to send and receive mail by specifying the desired settings. Then the user tries to send a message. If the setting is correct, the message will be delivered to the recipient. Most modern email services already have customized servers for sending messages. If you do not use third-party email software, you can send an email without making any additional settings on the site of the service where you have an account. Modern SMTP server administrators require users to authenticate before they can send their message. The user must first specify his login and on the server, and only then go to the shipment. This protection is used to block the possibility of sending spam using simple SMTP protocols. Previously, for the identification in the SMTP protocol, the unique IP address of the sender was used.

Электронный журнал «Столица Науки» СЕНТЯБРЬ 2(2) Bibliography 1. Johnson, K. Internet Email Protocols: A Developer's Guide. — Addison-Wesley Professional, 2000. — ISBN 0-201-43288-9. 2. Hughes, L. Internet e-mail Protocols, Standards and Implementation. — Artech House Publishers, 1998. — ISBN 0-89006-939-5.

Электронный журнал «Столица Науки» СЕНТЯБРЬ 2(2)