+#
+# single header signed
+exim -DOPT=From -odf a@test.ex
+From: nobody@example.com
+From: second@example.com
+
+content
+****
+#
+# single header, oversigned
+exim -DOPT=From:From -odf b@test.ex
+From: nobody@example.com
+
+content
+****
+#
+# default header set
+exim -DHEADERS_MAXSIZE=y -odf c@test.ex