This page shows how to use the mail() function in PHP for that purpose with examples:
PHP: mail - Manual

Please be aware that this form might be used to send SPAM to other users so you should add some form of verification like a CAPTCHA.

There are a couple of free scripts you can learn from here:

Search Listings | Hot Scripts

Hi Haroon & team (I can't tell who from the company is posting here),

You'll need to have a script on your web server that processes the form. The script will either send you an email, which you'll then receive in your regular email system. Or, the script will capture the contact form information into a database, and then show you the new database entries when you log on to the site with your administrative password.

I'm kind of surprised that you're asking, since both your sites already have a contact form. Do those forms not go anywhere yet?

Chris

following links might be useful..

ibdhost.com
freecontactform.com

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