EDIT: damn was i slow typer
Im asuming you already have a HTML <form> with the inputs in.
What you will need to do, is set the "action" of the form to something like "submit.php" and make sure that method is "post" (it can be GET as well, but you will be limited by URL char limit).
So the HTML for the form tag will look something like:
<form action="submit.php" method="post" ...other-attributes...>
You will also need to make sure you give your inputs a name, example:
<input type="text" name="email" />
Create a new file called submit.php. I will just post the php code which you can have anywhere within page. I would recomend at the top.
<?
//im declaring variables for easy use, you can use $_POST directly.
$email = $_POST['email'];
$subject = "Email from website"; // you could also have a $_POST here
$message = $_POST['message'];
$sendTo = "[email protected]";
$headers = "From:" . $from; // this is the headers of the email, i never really researched how emails work, so i dont know exactly how it works, but its basically declaring who the email is from. And im sure you can CCs and other things as well if you want.
mail($sendTo,$subject,$message,$headers);
?>
I wrote this code from scratch and have not tested it, but hopefully it will give you an idea of how you can do it. It can also be done in one page (as opose to having the form page and the submit.php page), but this would be slightly easier.