Determine who currently uses the existing legacy voicemail system. Learn how they use it so you can properly configure Unity to perform the same way.
One way to do accomlish this is to send questionaires or conduct a web based survey. Ask the users what they like about the current voicemail system and what feature(s) they'd like to have in a new voicemail system.
Divide your current users into groups, such as normal users, power users, special case users, administrators/receptionists and Executives. Document how these groups use voicemail today.
