+)
+
+## DKIM headers list.
+## Surprise! Internal whitespace isn't allowed here.
+DEFCONF(dkim_headers, m4_dnl
+References : In-Reply-To : Subject : To : Date : Message-ID : m4_dnl
+From : Sender : Reply-To : Cc : m4_dnl
+Content-Transfer-Encoding : Content-Type : MIME-Version : m4_dnl
+Content-ID : Content-Description m4_dnl