PHP Email not going via hostgator webmail

I am using corephp and i have used hostgator webmail to send email. Email is successfully going to some testing email provider like mailinator but it is not going to gmail,outlook and company email id.It is not in spam/junk as well. There is no error message recorded and it does not create any exception while sending email.

I am not getting what could be the reason?

This is my actual code.

<?php
require 'PHPMailerAutoload.php';

$mail = new PHPMailer;

$mail->isMail();                                      // Set mailer to use SMTP
$mail->Host = 'http://********/webmail'; // Specify main and backup SMTP servers
$mail->SMTPAuth = true;                               // Enable SMTP authentication
$mail->Username = 'username';                 // SMTP username
$mail->Password = 'password';                           // SMTP password
$mail->SMTPSecure = 'tls';                             // Enable encryption, 'ssl' also accepted

$mail->From = 'from@example.co';
$mail->FromName = 'Mailer';
$mail->addAddress('To@mailinator.com', 'ToUser');     // Add a recipient
$mail->addAddress('To@mailinator.com');               // Name is optional
$mail->addReplyTo('To@mailinator.com', 'Information');
$mail->addCC('cc@example.com');
$mail->addBCC('bcc@example.com');

$mail->WordWrap = 50;                                 // Set word wrap to 50 characters
$mail->addAttachment('/var/tmp/file.tar.gz');         // Add attachments
$mail->addAttachment('/tmp/image.jpg', 'new.jpg');    // Optional name
$mail->isHTML(true);                                  // Set email format to HTML

$mail->Subject = 'Here is the subject';
$mail->Body    = 'This is the HTML message body <b>in bold!</b>';
$mail->AltBody = 'This is the body in plain text for non-HTML mail clients';

if(!$mail->send()) {
    echo 'Message could not be sent.';
    echo 'Mailer Error: ' . $mail->ErrorInfo;
} else {
    echo 'Message has been sent';
}

Remove This Line from your coding

$mail->addAddress('To@mailinator.com');   

You Can Test With Gmail Account you will get mail on your junk mail box. you can report that mail as not a junk mail then you will get mails on outlook.

E.g:

$mail->addAddress('Toemailname@gmail.com', 'ToUser');