diff -up dovecot-2.0.beta4/dovecot-2-0-pigeonhole-940554ef4a55/src/managesieve/main.c.betahotfix dovecot-2.0.beta4/dovecot-2-0-pigeonhole-940554ef4a55/src/managesieve/main.c
--- dovecot-2.0.beta4/dovecot-2-0-pigeonhole-940554ef4a55/src/managesieve/main.c.betahotfix	2010-04-06 11:00:28.995085479 +0200
+++ dovecot-2.0.beta4/dovecot-2-0-pigeonhole-940554ef4a55/src/managesieve/main.c	2010-04-06 11:13:50.448016048 +0200
@@ -231,6 +231,14 @@ static void client_connected(const struc
 	}
 }
 
+static void login_client_failed(const struct master_login_client *client,
+				const char *errormsg)
+{
+	const char *msg;
+	msg = t_strdup_printf("* BAD %s\r\n", errormsg);
+	(void)write(client->fd, msg, strlen(msg));
+}
+
 int main(int argc, char *argv[])
 {
 	static const struct setting_parser_info *set_roots[] = {
@@ -284,7 +292,8 @@ int main(int argc, char *argv[])
 	} else {
 		master_login = master_login_init(master_service, "auth-master",
 						 postlogin_socket_path,
-						 login_client_connected);
+						 login_client_connected,
+						 login_client_failed);
 		io_loop_set_running(current_ioloop);
 	}