opendir my $dh, $pfx or return;
while (defined(my $bn = readdir($dh))) {
my $fl = maildir_basename_flags($bn) // next;
+ next if index($fl, 'T') >= 0;
my $f = $pfx.$bn;
my $eml = eml_from_path($f) or next;
my @kw = sort(map { $c2kw{$_} // () } split(//, $fl));