While you're listening to a message, you can access the following functions by pressing the relevant key on your phone:
0 to find out the caller's name and number.
1 to return the call.
2 to forward the message to a colleague.
4 to play the next message.
5 to repeat the message.
6 to listen to previously saved messages (after listening to all your new ones).
7 to delete the message.
9 to save the message.
Just press * to take you back to the dial-in service menu.