-my @OVERVIEW = qw(Subject From Date Message-ID References Xref);
-my $OVERVIEW_FMT = join(":\r\n", @OVERVIEW, qw(Bytes Lines)) . ":\r\n";
+my @OVERVIEW = qw(Subject From Date Message-ID References);
+my $OVERVIEW_FMT = join(":\r\n", @OVERVIEW, qw(Bytes Lines), '') .
+ "Xref:full\r\n";