This is what i am trying
$attach is the path to my excel => c:/xampp/htdocs/project/excel.xlsx
Notification::SendEmail('xyz@gmail.com', 'abc@gmail.com', "Subject","message", $attach);
If the$attach is removed then the email will go.
But it fails if i add the attachment
SendEmail function
    public static function SendEmail($mixFrom, $mixTo, $strSubject, $strMessage, $mixAttachment = null, $mixCc = null, $mixBcc = null) {
    // Declaration of Local Variables
    $strSMTPHost = QApplication::getSettingValue(Mssetting::SMTP_HOST);
    $strSMTPPort = QApplication::getSettingValue(Mssetting::SMTP_PORT);
    $objMessage = Swift_Message::newInstance($strSubject, $strMessage, 'text/html');
    // Set the source/destination data
    $objMessage->setFrom($mixFrom);
    $objMessage->setTo($mixTo);
    $objMessage->setCc($mixCc);
    $objMessage->setBcc($mixBcc);
    // Check for attachments
    if(is_array($mixAttachment)) {
        foreach($mixAttachment as $strFilePath)
            $objMessage->attach (Swift_Attachment::fromPath ($strFilePath));
    }
    elseif(is_string($mixAttachment)) {
        $objMessage->attach(Swift_Attachment::fromPath($mixAttachment));
    }
    // Setup the transport
    $objTransport = Swift_SmtpTransport::newInstance();
    if($strSMTPHost) $objTransport->setHost ($strSMTPHost);
    if($strSMTPPort) $objTransport->setPort($strSMTPPort);
    // Setup the mailer
    $objMailer = Swift_Mailer::newInstance($objTransport);
    // Send the message
    $objMailer->send($objMessage, $arrFailures);
    if($arrFailures)
        return $arrFailures;
    return true;
}