[smitha]

Hi,
How can i send emails using a linux OS.

[Cybertrion]

Install and configure sendmail (http://www.sendmail.org) on your Linux machine. Then try
$ mail user@host.tdn

[Whiteskin]

Sendmail can get confusing. It depends. Do you have an ISP account? Does your ISP have an SMTP server? Do you wish to recieve mail from your ISP/mail provider? If so, does your ISP/mail provider do POP3 or IMAP?

[smitha]

I ahev an SMTP server with a POP3 mail provider.Now how should i set the OS to receive mails?

[Cybertrion]

I see, at first I thought you wanted to run mail server and send e-mails by just typing mail user@domain.tdn at command prompt. Anyway, you can use
Pine (ncurses)
KMail (KDE Package)
Thunderbird (http://www.mozilla.org)

I am not sure if you would like Pine or not, but it isn't just GUI, I don't think beginners like it.
KMail is easy to set up, so is Thunderbird
Open KMail -> Settings -> Configure KMail -> Fill in Identities and Network -> Apply -> OK
When done, File -> Check mail in -> (The identity you set)
and it should start downloading e-mails, if you filled in everything correctly.

In Thunderbird it is Tools -> Account settings, it's all there.