I tried this on my own, and it worked...oddly enough, I got a warning that there wasn't the correct amount of arguements for mail(), but the email sent just fine.
LOL
Anyway, here is as basic as it gets:
<?php
$email = "mail@addy"; / insert the target email here /
$subject = "Subject"; / subject goes here /
$message= "Message"; / message goes here /
mail ($email, $subject, $message); / mail it out /
?>
Now, you will want to add some error handling, printing out that the mail was sent, and such, but this "should" work as-is.
For the php manual entry on mail() go here:
http://www.zend.com/manual/function.mail.php
You'll want to use some of the header's it lists so it says it's from who you want it to say it's from, and not from something like "Apache Server".
Enjoy 😉