Given a room is configured to not allow private messages. A participant sends a private message to another participant. The message is not delivered, instead an error message is returned. The error message is incorrect, because it says 'not-aceptable: Only participants can send messages to the room'. <message from='room1@conference.localhost/user1' type='error' to='user2@localhost/Tka'> <error type='modify' code='406'> <not-acceptable xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/> <text xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'>Solo los ocupantes pueden enviar mensajes a la sala</text> </error> </message> A more correct error message would be 'forbidden: The room configuration doesn't allow to send private messages to other participants'.