One of the simplest ways to use the PHP mail function in actual web application are as follows:

You need to define the required variables first and then use the mail function to finally send your mail.

I have done this with a lot of application and really works well, provided all required variables are validated first. Just my two cents.

The code is not shown above, by the way it is here:

$to = “whereyourliketosend@domain.com”;
$subject = “Your email subject here.”;
$message = “Your short message here”;
$from = “yourmail@domain.com”;
$headers = “From: $from”;
mail($to,$subject,$message,$headers);