What is SMTP Server? – Definition, Functions, Commands, And More

Definition SMTP Server

They are the acronym for “simple mail transmission protocol.” But, there is nothing simple for numerous of us: it is an additional practical term that is very unclearly understood. In reality, SMTP is part of the expertise that many of us use today regularly. What is an SMTP server, and what is it used? We will tell you.

The SMTP attendant is a computer in charge of loud out the SMTP service, temporary as an “electric postman.” It allows the conveyance of that email over the Internet. SMTP relay works very simply: if the SMTP server authorizes the sender and addressee identities, then the distribution is done.

Let’s say it’s like the web pole office: it collects the sender’s email and brings it to the recipient’s local post workplace, which is another SMTP server. It was born in 1982 and lasts to be the most extensively used Internet standard today.

To break this unhappy a bit more, let’s imagine the route your regular email would have to do at snail speed to reach its destination.

How does SMTP relay work?

We will explain the operation of the SMTP relay in a little more detail.

When an email is through the SMTP relay protocol, the validation of a series of text commands (of the ASCII character string) are subsequently sent to an SMTP server. Port 25 or 587 are generally using.

In this process, the content email does not come into play, but the attention of the SMTP language defines exclusively in the transmission.

Every time an email is sent using the SMTP protocol, a new session of the SMTP relay service is opening. Then, a series of information exchanges are carried out between the email client and the destination SMTP server, as if it were a conversation.

SMTP Commands

The conversation occurs using elementary text commands. The most mutual are the following:

  • HELO: to open a meeting with the server.
  • EHLO: to open a session in case the server supports extensions defined in RFC 1651.
  • MAIL FROM: to indicate who is sending the message.
  • RCPT TO: to display the recipient of the message.
  • DATA: to predict the beginning of the message, it will end when there is a line with only a dot.
  • QUIT: to close the session.
  • RESET: Aborts the current transaction and deletes all records.
  • SEND: Initiates a transaction in which the message is delivered to a terminal.
  • VRFY: Request the server to verify an entire argument.
  • EXPN: Asks the server to confirm the opinion.
  • HELP: This allows you to request information about a command.

Let’s look at an example of a friendly conversation between the email client and the SMTP server.

This exchange is initiated by the “EHLO” command, followed by the “MAIL FROM” command. MAIL FROM command will allow us to identify the sender.

Next, it is sent with the «RCPT» command that allows the server to identify the recipient. Then the «DATA» command, through which the content of the email is sent.

Finally, the command “QUIT” is sent, indicating the end of the exchange and the conversation between the email sending client and the server.

Every time this process occurs, the SMTP server will send the responses of these clients by email to warn if the commands are valid or not.

What type of SMTP server should you choose?

Use your SMTP server:

Establishing and maintaining an own SMTP server is usually an option for companies concerned with security and process control. Also as well as reliability of the service, as they sometimes do not know the standards that external providers can offer.

However, having your SMTP server is a task that can quickly become expensive and time-consuming. Using our technology implies allocating resources to its management and maintenance, and we cannot always count on the most outstanding advances or the best functions.

Also Read : E-Commerce – What Is An E-Commerce Business Website?

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