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Internet Applications
Published in Akshi Kumar, Web Technology, 2018
Mail delivery from an originating server to the destination server is handled by the Simple Mail Transfer Protocol (SMTP). The primary purpose of SMTP is to transfer email between mail servers. Some characteristics of SMTP are as follows: It is a client-server protocol where the client is the sending mail from an originating mail server to a receiving mail server.It allows reliable data transfer built on top of TCP (on port 25).It is a Push protocol where the sending server pushes the file to the receiving server rather than waiting for the receiver to request it.It is a Command/response interaction where commands are ASCII text and responses are three-digit status code and phrase.It is Synchronous as the sender awaits a response before issuing the next command.It has three phases of transfer: Handshaking, Transfer of messages, and Closure.
Common Standards in Cloud Computing
Published in John W. Rittinghouse, James F. Ransome, Cloud Computing, 2017
John W. Rittinghouse, James F. Ransome
SMTP was designed so that sender and recipient information could be transmitted with the message. The design process didn’t happen overnight, though. SMTP was initially defined in 1973 by IETF RFC 561. It has evolved over the years and has been modified by RFCs 680, 724 and 733. The current RFCs applying to SMTP are RFC 821 and RFC 822. SMTP is a two-way protocol that usually operates using TCP (Transmission Control Protocol) port 25. Though many people don’t realize it, SMTP can be used to both send and receive messages. Typically, though, workstations use POP (Post Office Protocol) rather than SMTP to receive messages. SMTP is usually used for either sending a message from a workstation to a mail server or for communications between mail servers.
Applications
Published in Khaleel Ahmad, M. N. Doja, Nur Izura Udzir, Manu Pratap Singh, Emerging Security Algorithms and Techniques, 2019
The changes included reducing the size of the e-mail, filtering, verification of header, machine learning for filtering SPAM, and scrupulous mails. SMTP is regarded as the standard protocol used for sending and receiving e-mails. Some security issues faced by SMTP are security and integrity. Since data of mail are not decrypted, it is present in the plain-text form (Jin, Takabi, & Joshi, 2010).
An M/G/1 queue with two types of general heterogeneous service and optional repeated service subject to server’s breakdown and delayed repair
Published in Quality Technology & Quantitative Management, 2018
Gautam Choudhury, Chandi Ram Kalita
Consider a digital communication network system, where mail server transmits the email data from one station to another station. In emailing process, the Mail servers can be broken down into two main categories: outgoing mail servers and incoming mail servers. Outgoing mail servers are known as SMTP, or Simple Mail Transfer Protocol, servers. Incoming mail servers come in two main varieties. POP3, or Post Office Protocol, version 3, servers are best known for storing sent and received messages on PCs’ local hard drives. IMAP, or Internet Message Access Protocol, servers always store copies of messages on servers. After composing a message and hitting send, sender’s email client – whether it’s Outlook Express or Gmail – connects to its domain’s SMTP server. The sender’s email client communicates with the SMTP server, giving it sender’s email address, the recipient’s email address, the message body and any attachments. The SMTP servers process the recipient’s email address – especially its domain and then perform two types of job. In the first type of job it routed the message directly over to the domain’s POP3 or IMAP server, if the domain name is same as the sender’s and in the second type of job the SMTP server send message to the other domain’s server (DNS) if the domain name is different with sender’s. Typically, message processing request arrive at the SMTP server following Poisson stream and message can select any one of the two types of service at the SMTP server (depending upon the choice of the sender, the sender may send message with same or different domain name as recipient’s). The sender can resend the message again due to failure of the previous sending. In practice message processing request may fail due to failure of the SMTP server. After failure of the SMTP server, the server can be repaired. The repair time depends on the degree of failure of the SMTP server. Because the system performance may be heavily affected by SMTP server breakdown, it is well worth to investigate such system from the queueing theory point of view, as well as reliability point of view. In this scenario, the SMTP server, two types of job by SMTP server, message resend correspond to the server, two types of service and repeated service in the queueing terminology.