Сообщение не может быть отправлено. Ошибка отправителя: сбой SMTP connect () Сообщение не может быть отправлено. Ошибка отправителя

 <?php
include('libs/PHPMailer-master/PHPMailerAutoload.php');
//require 'PHPMailerAutoload.php';
//require 'system/includes/PHPMailer/PHPMailerAutoload.php';
$mail = new PHPMailer;

//$mail->SMTPDebug = 3;                               // Enable verbose debug output

$mail->isSMTP();                                      // Set mailer to use SMTP
$mail->Host = gethostbyname("hostName");  // Specify main and backup SMTP servers
$mail->SMTPAuth = true;                               // Enable SMTP authentication
//$mail->Username = 'user@example.com';                 // SMTP username
//$mail->Password = 'secret';                           // SMTP password
$mail->SMTPSecure = 'tls';                            // Enable TLS encryption, `ssl` also accepted
$mail->Port = 587;                                    // TCP port to connect to

$mail->setFrom(ex@com.lk, 'Mailer');
$mail->addAddress('ex@com.lk', 'Joe User');     // Add a recipient
//$mail->addAddress('ellen@example.com');               // Name is optional
//$mail->addReplyTo('info@example.com', 'Information');
//$mail->addCC('cc@example.com');
//$mail->addBCC('bcc@example.com');

//$mail->addAttachment('/var/tmp/file.tar.gz');         // Add attachments
//$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';
}
?>