Not 100% sure but you can try this hack.
Open components\com_virtuemart\helpers\shopfunctionsf.php
Find the following codes between lines 274 to 288:
if(isset($view->doVendor) && !$noVendorMail) {
if(isset($vars['orderDetails'])){
$order = $vars['orderDetails'];
$orderstatusForVendorEmail = VmConfig::get('email_os_v',array('U','C','R','X'));
if(!is_array($orderstatusForVendorEmail)) $orderstatusForVendorEmail = array($orderstatusForVendorEmail);
if ( in_array((string)$order['details']['BT']->order_status,$orderstatusForVendorEmail)){
self::sendVmMail( $view, $view->vendorEmail, TRUE );
}else{
$user = -1;
}
} else {
self::sendVmMail( $view, $view->vendorEmail, TRUE );
}
}
Replace above by:
if(isset($view->doVendor) && !$noVendorMail) {
if(isset($vars['orderDetails'])){
$order = $vars['orderDetails'];
$orderstatusForVendorEmail = VmConfig::get('email_os_v',array('U','C','R','X'));
if(!is_array($orderstatusForVendorEmail)) $orderstatusForVendorEmail = array($orderstatusForVendorEmail);
if ( in_array((string)$order['details']['BT']->order_status,$orderstatusForVendorEmail)){
self::sendVmMail( $view, $view->vendorEmail, TRUE );
}else{
$user = -1;
}
}
}