AASTRA 4225 for MX-ONE Telephony Switch - Manual (Page 81)

81 Dialog 4223 Professional/Dialog 4225 Vision
Messages
Message Waiting
If assigned this feature and your phone is diverted to an interception
computer, a function key (preprogrammed by your system
administrator) will flash when there are messages stored for you in the
computer. The messages will be printed out on a printer connected to
the computer.
To print out messages
Message
Х Ф
Press.
Note: The function key is preprogrammed by your system
administrator.
The display shows the identity of the computer and the number of
messages stored for you.
If you find that the notification of Message Waiting is intrusive or you
want to shut off the notification:
#91#*
Dial.
Acknowledgement tone.