fire failed sms events

src/switch_loadable_module.c

@@ -579,13 +579,22 @@ static switch_status_t do_chat_send(switch_event_t *message_event)
 	}
 	
 	if (!do_skip && !switch_stristr("GLOBAL", dest_proto)) {
-		if (!(ci = switch_loadable_module_get_chat_interface(dest_proto)) || !ci->chat_send) {
-			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Invalid chat interface [%s]!\n", dest_proto);
-			return SWITCH_STATUS_FALSE;
-		}
+		if ((ci = switch_loadable_module_get_chat_interface(dest_proto)) && ci->chat_send) {
 			status = ci->chat_send(message_event);
 			UNPROTECT_INTERFACE(ci);
+		} else {
+			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Invalid chat interface [%s]!\n", dest_proto);
+			status = SWITCH_STATUS_FALSE;
 		}
+	}
+
+	if (status != SWITCH_STATUS_SUCCESS) {
+		switch_event_t *dup;
+		switch_event_dup(&dup, message_event);
+		switch_event_add_header_string(dup, SWITCH_STACK_BOTTOM, "Delivery-Failure", "true");
+		switch_event_fire(&dup);
+	}
+
 
 	return status;
 }