Do you mean you create a list in MaxBulk Mailer and then try to upload it? Are you use MLM is properly installed? Have you tried to log into MLM with your browser, add a list and add a recipient to it? Any error?
$dbhost = 'cpanel17.uk2.net'; // mySQL Host Name (if you need to set the port add ortnum)
$dbusername = 'account username'; // mySQL User Name (For Full access!!)
$dbuserpass = 'my password'; // mySQL User Password (For Full access!!)
$dbname = 'username_mlm'