- my $refs = $hdr->header_raw('References');
- my @refs = $refs ? ($refs =~ /<([^>]+)>/g) : ();
- my $irt = $hdr->header_raw('In-Reply-To');
- if (defined $irt) {
- $irt = mid_clean($irt);
- $irt = undef if $mid eq $irt;
- }
+
+ # last References should be IRT, but some mail clients do things
+ # out of order, so trust IRT over References iff IRT exists
+ my @refs = ($hdr->header_raw('References'),
+ $hdr->header_raw('In-Reply-To'));
+ @refs = ((join(' ', @refs)) =~ /<([^>]+)>/g);