if (defined $arg{User}) {
       $obj->auth($arg{User},$arg{Password});
}


##</code><code>##

        MIME::Lite->send('smtp', $out_smtp ,
                          Port =>$smtp_port ,
                          Timeout=>60 ,
                          Debug => $debug ,
                          Hello => 'domain.com',
                          User  => 'trs80',
                          Password  => 'blah' );