Basic functions of the new phones will work the same as your current phone - such as dialing, hold, and speakerphone. For more advanced features - including voicemail - you may need to refer documentation provided or attend a training session via this link - http://itsblog.manhattan.edu/p/telephone-system-upgrade-2013.html
There will be an announcement the week of 3/18 providing instructions on how to access the new voicemail system. Users will be required to activate their new voicemailbox. Optionally, you will be able to enable and configure advanced features such as voicemail-to-email.
Thank you for your patience and cooperation throughout this upgrade.