Envío de correos electrónicos a través de SMTP con PHPMailer

Estoy tratando de enviar correos electrónicos SMTP usando PHPMailer, pero sigo recibiendo este mensaje de error, ¿alguna idea de cómo deshacerme de él?
Estoy tratando de conectarme a través de SSL en el puerto 465.

SMTP -> FROM SERVER: 
SMTP -> FROM SERVER: 
SMTP -> ERROR: EHLO not accepted from server: 

Notice: fputs() [function.fputs]: send of 18 bytes failed with errno=32 Roura přerušena (SIGPIPE) in /home/www/amazonek.cz/subdomains/library/PHPMailer_v5.1/class.smtp.php on line 494
SMTP -> FROM SERVER: 
SMTP -> ERROR: HELO not accepted from server: 

Notice: fputs() [function.fputs]: send of 12 bytes failed with errno=32 Roura přerušena (SIGPIPE) in /home/www/amazonek.cz/subdomains/library/PHPMailer_v5.1/class.smtp.php on line 212
SMTP -> ERROR: AUTH not accepted from server: 
SMTP Error: Could not authenticate.

Mi código:

  require_once('../library/PHPMailer_v5.1/class.phpmailer.php');

        try{
            $mail = new PHPMailer(true);
            $mail->IsSMTP();
            $mail->SMTPAuth = true;
            $mail->Host = SMTP_SERVER;
            $mail->Port = SMTP_PORT;
            $mail->Username = SMTP_USERNAME;
            $mail->Password = SMTP_PASSWORD;
            $mail->SMTPDebug = 2;
            $mail->SetFrom(MAIL_ORDERS_ADDRESS, MAIL_ORDERS_NAME);
            $mail->Subject = 'AMAZONEK.cz - objednávka číslo '.$_SESSION['orderId'];
            $mail->MsgHTML('<b>Ahoj</b>');
            $mail->AddAddress($_SESSION['user']['email'], $_SESSION['user']['name'].' '.$_SESSION['user']['surname']);
            $mail->AddBCC(MAIL_ORDERS_ADDRESS, MAIL_ORDERS_NAME);

            if(!$mail->Send()) throw new Exception($mail->ErrorInfo);
        }
        catch(Exception $e){
            echo $e->getMessage();
        }

Definición de constantes:

define('SMTP_SERVER', 'smtp.ebola.cz');
define('SMTP_PORT', 465);
define('SMTP_USERNAME', 'myEmail@myDomain.tld');
define('SMTP_PASSWORD', '***CENSORED***');

define('MAIL_ORDERS_ADDRESS', 'myEmail@myDomain.tld');
define('MAIL_ORDERS_NAME', 'My Name');

¿Algunas ideas?