https://devzone.nordicsemi.com/f/nordic-q-a/84116/why-the-message-would-be-send-twiceHi,there: I was used 2 52832 board to run the linght switch server/client examples to test message communication. I add the mesh events handle like this: Then run the client and server at the 2 board , i send the message on the client by press theen-USTelligent Community 13Thu, 27 Jan 2022 15:13:51 GMThttps://devzone.nordicsemi.com/thread/350025?ContentTypeID=1Thu, 27 Jan 2022 15:13:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:48116a39-83a0-4d9b-82cd-f3242a47a81fsipan112<p>The messaging protocols, including the proprietary MGP, all include functionality to send and receive messages.</p> <p>In general, messages are kept in the queue for the connector through which they should be sent until successfully sent or until a permanent error has occurred. Most errors are considered temporary though and will cause the message to stay in the queue for further delivery attempts. When a temporary error has occurred for a message it is put at the end of the queue in order for other messages to be delivered meanwhile. It is possible to specify a maximum number of delivery attempts after which the message will be considered undeliverable and will be removed from the queue.</p><div style="clear:both;"></div>