SMTP Full Form

SMTP usually stands for Simple Mail Transfer Protocol. This is a TCP/IP protocol used in sending and receiving emails. SMTP was widely used in the 1980s. That time this was a complement to unix to unix copy program (UUCP) mail. Which was suitable for handling email transfers between the machines that were intermittently connected with each other. This was the first successful attempt to evolve into sending mail. General feature of SMTP is that this system needs a reliable ordered data stream channel. The Simple Mail Transfer Protocol has two types, ie; end to end method and another one is store and forward method. Which will be discussed later elaborately. Using a method, named “store and forward” SMTP can move email over and across networks. This usually works with Mail Transfer Agent (MTA). By using Store and Forward which has already been mentioned earlier, messages can be moved from one computer to another device. But SMTP only can forward text, not any graphics, images, fonts or any type of attachments. 

COMPONENTS OF SMTP:

There are four components in SMTP. 

1. MUA (mail User Agent): this allows the client to receive and send emails.
2. MSA (mail submission agent): This one is the server that receives data from MUA and helps to deliver via MTA. 
3. MTA (mail transfer agent): This helps in receiving mail from local agents and forward for the delivery. 
4. MDA (mail delivery agent): This delivers the email to the confined mailbox. 

HOW SMTP works? 

The working process of SMTP is a four step process which is built on the server model. 

Step 1. Submission of the mail: The client submits the finished mail to the SMTP server by using TCP port 25. 

Step 2. Delivery of the mail: SMTP server splits the sender’s mail address in two parts. Sender’s domain name and username. If domain and username both are same then it directs the mail to POP3 for domain. 

Step 3. Receive and process the mail: after receiving incoming mail the trade server conveys the mail to the incoming server that holds the email as late as the user gets it. 

Step 4. Access and the recovery of the mail: The mail which is already stored in the MDA can be recovered by mail user agent or MSA that can be approached by login id and the particular password. 

PORTS: 

Transmission between mail servers uses TCP port 25 deputed for SMTP. 

• 587, as codify in RFC 6409
• 465, was deplored after RFC 2487

PURPOSE: 

• The main purpose of SMTP is to transfer mail between mail servers. Though this is difficult for mail agents as well. In case of sending emails the client usually sends an email to an outgoing email server. Which connects the destination mail server for delivery. For this, it is important to specify an SMTP server while configuring a client.

• SMTP server does not require any authentication. It allows anyone on the internet to send mail to anyone else or even in large groups. So that it makes junk mail or spam messages. 

BINARY DATA TRANSFER: 

SMTP supports only single body text, and the Binary data requires to be coded in format of text into the message body before transferring. 

LIMITATIONS OF SMTP: 

The basic limitations of using SMTP is that this system is not secure and can be hacked easily. Fake emails and messages can be sent by using any IP address to one recipient. There are few rules and regulations for using SMTP, so users have to maintain and go through the rules and regulations. This system allows users to synchronise a server. 

CONCLUSION:

SMTP is a process which helps to send and receive data in the form of text or message via mail from sender to recipient. This process has a wide use for different purposes. Though there are many limitations, still till date this method is popular among mail user agents. There are some security issues in the SMTP process thus spam message or junk issues are there. Also this mail can be hacked easily. But it gives the solution to send mail and messages to too many people. Also emailing in bulk can be processed through this. 

SMTP is an essential email marketer. The client just needs to choose accordingly.