Simple Mail Transfer Protocol which is shortly known as SMTP and it is a protocol which is being used for the communication process for the electronic mail transmission. Mail servers and all the other agents utilize this SMTP protocol to mail and receive the messages through mail. The proprietary systems like the IBM and Microsoft exchange and other webmail systems like yahoo, Gmail, outlook uses non standard protocols internally but they will use SMTP to send and receive the messages from outside their systems. The user level email clients mostly use SMTP only for sending the mails.  

The history of simple mail transfer protocol: 

The SMTP became widely used in the 1980’s and at that time Unix to Unix copy program mail was best suited for handling the email transfers between the machines and the SMTP was used to send and receive the messages which have been connected to the networks. Both the protocols use store and forward mechanism which is the best example of push technology.  

The SMTP is a linked based protocol through which the mail sender and the receiver communicate by sending the commands which is normally a TCP.  Simple mail transfer protocol consists of a client and server system where the client requests information to sever and then server accepts and sends back the information to the client. This session may contain zero or many numbers of SMTP transactions. It contains of three commands or reply sequences and those are given below: 

  • Mail command which is used to begin the revert address which is called return path. 
  • RCTP command, which is done to establish the receiver of the message.  
  • DATA which is used to establish the start of the message passage. This consists of a message header and the message body which is being separated by the empty line.  

Advantages of SMTP server: 

As SMTP is the communication protocol and it is being used for sending and receiving the messages through mails. You can know more at This protocol is a simple one and has the following advantages: 

  • This SMTP server is the most reliable email server for sending and receiving the messages to clients or customers. 
  • Email is sent through the simple process from the SMTP servers.  
  • This is most cost effective way because we can send to large number of people at one time. 
  • We can send and receive messages easily and quickly from one place to another. 
  • Through this server, we can easily track the status of the emails.  
  • SMTP server helps to reach your mail to the inbox of the recipients without fail.  
  • You can easily send a large file or the documents through the mail by using this server.  

As this SMTP servers are simple to configure and also can help to manage the things with respect to the email deliverability. And also it gives you the flexibility to prioritize the email delivery based on your needs.