elsif (/^Content-Transfer-Encoding: (.*)/i) {
                                $xfer_encoding = $1 if not defined $xfer_encoding;
                        }
+                       elsif (/^In-Reply-To: (.*)/i) {
+                               $in_reply_to = $1;
+                       }
+                       elsif (/^References: (.*)/i) {
+                               $references = $1;
+                       }
                        elsif (!/^Date:\s/i && /^[-A-Za-z]+:\s+\S/) {
                                push @xh, $_;
                        }
-
                } else {
                        # In the traditional
                        # "send lots of email" format,