9696d660_Exchange_Voice_Mail_User_Guide__Description
[Feature] Reset my Voice Mail PIN [How to Enable or Disable] See How to Enable/Disable Additional Features [Description] 
Resets your PIN and gives you a temporary PIN in an email message. When you log on to your voice mail with that PIN, a voice prompt will say the PIN has expired and you'll be asked to create a new PIN.
ITS Exchange Voice Mail User Guide
Description