Panasonic KX-TG2239B Manuel D’Utilisation

Voice mail service is an electronic on-line answering system offered by
your telephone company. After subscribing, the voice mail system can
answer calls automatically for you when your line is busy or if calls are not
answered, and caller can leave their messages at the voice mail box
virtually located at the telephone company. After the voice mail box has
received messages, the unit will indicate it in two ways: 
(a) “Voice mail” displayed on the handset, and (b) the VM indicator on
the base unit will flash. 
To use this feature, you must first store your access number (p. 50).