Basic discussion about mail server

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Really thanks to you for your interest in this topics. :)

We use mail for mainly communication purpose. Daily so many mails are sending and receiving by the users.  Generally these are handled by email server. So, lets discuss something about the mail server.

Basic discussion about mail server

What is email?

E-Mail generally stands for Electronic mail.

It offers a fast, economical means of transferring messages anywhere in the world.

Email address:

Now lets come to the point, what is email address. Generally it can say that, the address through which you can communicate with each other and others also can communicate with you, can be treated as email address.

lets have a email address :  alornishan1@gmail.com

In this email address, alornishan1 is the user name.

and gmail.com is the domain name of email server.

Here you can see, the username and domain name is separated by a “@” sign.

Now come to the point about the email server and email client

¢Email client (is also known as MUA- Mail User Agent) – software / program that can transfer e-mail from a local host to a local email server.

¢Email server – software/program that can send/receive e-mail from/to other email servers. MTA (Mail Transfer Agent) and/or MD (Mail Delivery Agent).

¢Mailbox – An electronic mailbox is a disk file which holds email messages. Generally sent mail and received mails are located in different folder.

In the email you find the option CC (Carbon copy) and BCC (Blind Carbon Copy).

¢Carbon Copy Section

—Send a message to more than one person, all the recipients will see the list of email addresses.

¢Blind Carbon Copy Section

—The addresses won’t be seen by the recipients. When email is sent to a large group of people who don’t know each other.

Now lets come to the point what is server which serves mail:

Email server is generally an application, which receives mail from the email client and from other mail server. Every email we sent, is sent passes through a series of mail servers and goes its way to its intended recipient. Actually in this transfer case, a series of complex transfer takes place.

Now you can ask the question – Why this complex series needed in the case of transferring a mail?

The answer is that, without this series of mail servers, one can only be able to send emails to the people whose email address domains matched with your own.

 

SMTP : Simple Mail Transfer Protocol

¢Simple Mail Transfer Protocol (SMTP) is a standard set of rules and procedures by which messages can be transferred over the Internet. It is used by Mail Servers to send messages back and forth to other Mail Servers or Email Clients.

¢List of SMTP commands:

HELO
RCPT  TO
MAIL  FROM
DATA
QUIT

POP : Post Office Protocol (POP3)

¢In order to collect email messages from the Mail Server, the Email Client contacts the Mail Server and supplies it with an account “user” name and a password.

¢List of POP commands:

USER
PASS
STAT
RETR 1
DELE 1

¢Advantages

—Don’t have to know the name of your machine.

—POP mail server is installed on a computer always ON.

—Use Windows interface to read email.

¢Disadvantages

—The mail at the email server is popped to your local machine.

 

If you want to configure mail server in centOS, then you need to have three packages. They are:

1. Postfix – SMTP
2. Dovecot – POP3
3. SquirrelMail – Web Interface