rem: if ( mParameter.isEmpty() ) return ErrorButGoOn; msg->setHeaderField( "X-KMail-Transport", mParameter );
add: KMMessage *bounceMsg = msg->createBounce( FALSE ); if ( !bounceMsg ) return ErrorButGoOn;    kernel->msgSender()->send( bounceMsg, FALSE );
context: KMFilterAction::ReturnCode KMFilterActionTransport::process(KMMessage* msg, bool& ) const{  if ( mParameter.isEmpty() )    return ErrorButGoOn;  msg->setHeaderField( "X-KMail-Transport", mParameter );  return GoOn;}