Introduction To SMTP and POP3: How it all Works

SMTP is part of the application layer of the TCP/IP protocol. Using a process called “store and forward,”. It moves your email on and across networks. the Mail Transfer Agent (MTA) to send your communication to the right come So it works closely with something referred to as puter and email inbox.

The client who wants to send the mail opens a TCP connection to the SMTP server and then sends the mail across the relationship.  The SMTP server is constantly in listening mode. As soon because it listens for a TCP connection from any client, the SMTP procedure initiates a connection on that port (25). After successfully establishing the TCP connection the client process sends the mail instantly.

SMTP at work

It provides a set of codes that simplify the communication of email messages between email servers. It is a kind of shorthand that allows a server to break up different parts of a message into categories the other server can understand. When you send a message out, it was strings of text which can be separated through the code words (or numbers) that identify the purpose of each section.

SMTP provides those codes, and email server software designed to understand what they mean. As each message travels towards its destination, it sometimes passes through a number of computer systems as well as their single  MTAs. As it does, it’s briefly stored before it moves on to the next computer in the path.

Outgoing Email Server – SMTP

It stands for Simple Mail Transfer Protocol. It handles the sending of emails.

The ability to support email services includes two critical functions: SMTP and POP3. Together, they allow the user to send outgoing mail and retrieve incoming mail, respectively.

The SMTP server performs two basic functions:

  1. It verifies that anyone attempting to send outgoing email through the SMTP server.
  2. It sends the outgoing mail and if undeliverable, sends the message back to the sender.

POP3 Email Accounts

POP3 is the oldest internet message access protocol. It was designed to assist offline/local email processing. Email delivered to a mail server and a faraway email client periodically downloads the email from the server to the customer’s computer.

Once the messages delivered, they deleted from the mail server, although customers can configure their email client to leave a copy of the email on the mail server.

POP3 email accounts require an email client to send and receive emails. Common email customers include Netscape Messenger, Outlook specific, and more.

when you check your email using an email client, it makes a connection in your mail server and downloads your emails on your computer. Observe that POP3 handles mail access (or mail retrieval) only. Email sending is handling by SMTP.

Advantages of POP3

  • All emails downloaded to your computer. So you can read your emails without being logged onto the Internet.
  • Opening attachments are easy and quick as the file already downloaded on to your computer.

Disadvantages of POP3

  • All messages downloaded on to the accessing email client/computer.
  • Hence which means that the user will want to go again to the same computer to access the emails.


Leave a Reply