PHP Mailer doesn't seem to work - php

Question

I'm working on a registration page on a website where I need to implement a email verification.
I have installed PHPMailer-master on the server. The first part of the code is written directly in the registration php:
include('send_mail.php');
$to=$email;
$subject="Email verification";
$body='Hi, <br/> <br/> thank you for joining us! Please verify your email and get started using your account. <br/> <br/> '.$base_url.'activation/'.$activation.'';
Send_Mail($to,$subject,$body);
$msg= "Registration successful, a verification email has ben sent to you. Please activate this to get started.";
And the code in send_mail.php:
<?php
function Send_Mail($to,$subject,$body)
{
require 'PHPMailer-master/class.phpmailer.php';
require 'PHPMailer-master/PHPMailerAutoload.php';
$from = "*mywebsite*";
$mail = new PHPMailer();
$mail->IsSMTP(true); // use SMTP
$mail->IsHTML(true);
$mail->SMTPAuth = true; // enable SMTP authentication
$mail->Host = "*my webhost's mailserver*"; // SMTP host
$mail->Port = 465; // set the SMTP port
$mail->Username = "*username*"; // SMTP username
$mail->Password = "*password*"; // SMTP password
$mail->SetFrom($from, '*mywebsite?*');
$mail->AddReplyTo($from,'*mywebsite?*');
$mail->Subject = $subject;
$mail->MsgHTML($body);
$address = $to;
$mail->AddAddress($address, $to);
$mail->Send();
}
?>
I'm fairly sure the information in send_mail.php is correct. I'm using the information I found on my configure mail client page on cPanel ("Secure SSL/TLS Settings").
When I try to register, the website goes white somehow. The account gets created on phpmyadmin. No error-log in public_html.
Any ideas?
UPDATE: Sorry for late response.
I've tried using the PHPMailer Test Page. When I try SMTP, the page just loads forever. When using Sendmail, I get the error "Could not execute: /usr/sbin/sendmail -t -i". When I use the QMAIL, it says the email was sent but I never recieve it.
BUT... when I use Mail, I recieve it successfully. Is "Mail" secure enough to use? What are the differences? And how should I implement it into the php code of the register page? I can't find any specific part in the PHPMailer Test Page code for the "mail" function.
Code looks like this now:
$email = $_POST['email'];
require 'PHPMailer-master/PHPMailerAutoload.php';
$mail = new PHPMailer(true);
try {
$mail->AddReplyTo('myemail');
$mail->AddAddress($email);
$mail->SetFrom('myemail');
$mail->AddReplyTo('myemail');
$mail->Subject = 'subject';
$mail->Message = 'message comes here';
$mail->Send();
echo "Message Sent OK<p></p>\n";
} catch (phpmailerException $e) {
echo $e->errorMessage();
} catch (Exception $e) {
echo $e->getMessage();
}
Error message: "Message body empty"