. . .

  if ($code == 000 ||                   # got here w/ no resp
      $code == '021' || $code == 421 || # server timeout || abort
      $code == 425 ||      # connection not opened ('out of ports'?)
      $code == 150) {      # intermediate result (never finished)

    $code < 100  and warn " No response (Timeout?).\n";
    150 == $code and warn "\tTimed out in mid-operation.\n";
    421 == $code and warn "\tServer disconnected.\n";
    425 == $code and warn "\tRestarting to clear connections.\n"
                  and sleep 10;
    warn "attempting to reconnect? ...\n";

    undef $_[0];
    return undef;
  }

  if ($code == 530) {     # not logged in! ** needs to croak() **
    die "Can't seem to login!
   (check ~/.netrc file or give name and password on command line?).
          (I'm dieing) \n";
  }

  if ( $code == 550   # dir/file not available (non-exist, no perms)
       || (500 <= $code && $code <= 504)   # syntax errors
       || $code == 553                     # illegal file name
       || $code == 452 || $code == 552 ) { # out of space(552: quota)
    return '';
  }

  if ($code == 426                     # closed early
      || $code == 450 || $code == 451  # file busy, srvr local error
      || $code == '051') {             # added this: local rcv error

    warn "\tTemporary failure, retrying...\n";
    sleep 12;
    return undef;                           # retry
  }