data_headers_end does not work in async mode

docs/plugins.pod

@@ -787,6 +787,8 @@ B<NOTE:> BE CAREFUL! If you drop the connection legal MTAs will retry again
 and again, spammers will probably not. This is not RFC compliant and can lead
 to an unpredictable mess. Use with caution.
 
+B<NOTE:> This hook does not currently work in async mode.
+
 Why this head may be useful for you, see 
 L<http://www.nntp.perl.org/group/perl.qpsmtpd/2009/02/msg8502.html>, ff.
 

lib/Qpsmtpd/SMTP.pm

@@ -666,6 +666,8 @@ sub data_respond {
 
         $self->transaction->header($header);
 
+	# NOTE: This will not work properly under async.  A
+	# data_headers_end_respond needs to be created.
         my ($rc, $msg) = $self->run_hooks('data_headers_end');
         if ($rc == DENY_DISCONNECT) {
           $self->respond(554, $msg || "Message denied");