Forms and effect of "return false" in form.php

I Need Help
1

I have created a self hostet form in Blocs. Everything is working fine. Now I wanted to modify the form.php file in the incluces folder. I expected that “return false” would show the fail message and “return true” would show the success message. So I changed the second last line in the form.php file from “return true” to “return false”. Strangely enough, I noticed no change in the behaviour of the form, i.e. the success message is displayed.

So my question is: What effect does “return false” have in the form.php file?

<?php	
	if (empty($_POST['name']) && strlen($_POST['name']) == 0 || empty($_POST['email']) && strlen($_POST['email']) == 0 || empty($_POST['message']) && strlen($_POST['message']) == 0)
	{
		return false;
	}
	
	$name = $_POST['name'];
	$email = $_POST['email'];
	$message = $_POST['message'];
	
	$to = 'info@xyz.com'; // Email submissions are sent to this email

	// Create email	
	$email_subject = "Message from a Blocs website.";
	$email_body = "You have received a new message. \n\n".
				  "Name: $name \nEmail: $email \nMessage: $message \n";
	$headers = "MIME-Version: 1.0\r\nContent-type: text/plain; charset=UTF-8\r\n";	
	$headers .= "From: info@xyz.com\r\n";
	$headers .= "Reply-To: $email";	
	
	mail($to,$email_subject,$email_body,$headers); // Post message
	return false;	// was "return true" before		
?>