my $subj = $hdr->header('Subject') || '';
$subj = "Re: $subj" unless $subj =~ /\bRe:/i;
my $mid = $hdr->header_raw('Message-ID');
push @arg, '--in-reply-to='.squote_maybe(mid_clean($mid));
my $irt = mid_escape($mid);
delete $cc->{$to};
my $subj = $hdr->header('Subject') || '';
$subj = "Re: $subj" unless $subj =~ /\bRe:/i;
my $mid = $hdr->header_raw('Message-ID');
push @arg, '--in-reply-to='.squote_maybe(mid_clean($mid));
my $irt = mid_escape($mid);
delete $cc->{$to};